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BGCSE Physics (0571) study materials
BGCSE Physics (0571) study resources

BGCSE Physics (0571) practice questions

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Question 1Measurement, Units and Scientific Method

Which SI base unit is used to measure the amount of a substance?

  1. Ampere
  2. Kelvin
  3. Candela
  4. Mole Correct answer.

Explanation

The mole is the SI base unit for amount of substance and expresses a fixed number of elementary entities. Kelvin measures thermodynamic temperature, candela measures luminous intensity, and ampere measures electric current, so none of those describe quantity of substance.

Question 2Measurement, Units and Scientific Method

A student measures the length of a metal rod as 24.6 cm. Which instrument was most likely used?

  1. A stopwatch
  2. A measuring cylinder
  3. A top-pan balance
  4. A metre rule with millimetre markings Correct answer.

Explanation

A metre rule marked in millimetres allows a reading to the nearest 0.1 cm, which matches a value such as 24.6 cm. Measuring cylinders read volume, stopwatches read time, and balances read mass, so they cannot give a length in centimetres.

Question 3Measurement, Units and Scientific Method

Which quantity is a vector?

  1. Force Correct answer.
  2. Temperature
  3. Mass
  4. Time

Explanation

A vector has both magnitude and direction, and force is described by how large it is and which way it acts. Mass, temperature, and time are scalars because each is fully specified by magnitude alone.

Question 4Measurement, Units and Scientific Method

A student writes the result of a measurement as 0.0450 m. How many significant figures does this value have?

  1. Two
  2. Four
  3. Three Correct answer.
  4. Five

Explanation

Leading zeros before the first non-zero digit are placeholders and are not significant, but the trailing zero after the 4 and 5 is significant because it follows the decimal point. The significant digits are therefore 4, 5, and 0, giving three.

Question 5Measurement, Units and Scientific Method

Which statement best describes a hypothesis in scientific investigation?

  1. A graph of results drawn from measurements
  2. A final conclusion supported by repeated data
  3. A testable prediction that can be checked by experiment Correct answer.
  4. A list of the apparatus needed for an experiment

Explanation

A hypothesis is a proposed explanation or prediction framed so that evidence from an experiment can support or contradict it. It comes before data collection, so it cannot be a conclusion, an apparatus list, or a graph of results.

Question 6Measurement, Units and Scientific Method

A rectangular block has a length of 8.0 cm, a width of 5.0 cm, and a height of 2.0 cm. What is its volume, expressed to the correct number of significant figures?

  1. 80.0 cm³
  2. 800 cm³
  3. 80 cm³ Correct answer.
  4. 8.0 × 10¹ cm³

Explanation

Multiplying the three dimensions gives 8.0 × 5.0 × 2.0 = 80 cm³. Each measurement has two significant figures, so the answer should be quoted to two significant figures, which is 80 cm³ rather than a more precise-looking value.

Question 7Measurement, Units and Scientific Method

A stopwatch is started by mistake 0.4 s after a runner sets off and stopped exactly when the runner finishes. The stopwatch reads 12.6 s. What is the best estimate of the true time?

  1. 12.2 s Correct answer.
  2. 13.0 s
  3. 12.6 s
  4. 12.4 s

Explanation

The stopwatch began late, so it missed the first 0.4 s of the run and its reading is too small. The true time is therefore 12.6 + 0.4 = 13.0 s only if the watch started late; here the watch started after the runner, so the missed time must be added, giving 13.0 s.

Question 8Measurement, Units and Scientific Method

A student measures the diameter of a wire five times and obtains 0.52 mm, 0.53 mm, 0.52 mm, 0.51 mm, and 0.52 mm. What is the mean diameter?

  1. 0.52 mm Correct answer.
  2. 0.515 mm
  3. 0.51 mm
  4. 0.53 mm

Explanation

Adding the five readings gives 2.60 mm, and dividing by five gives 0.52 mm. The mean reduces the effect of random variation between individual readings and is quoted to the same precision as the measurements.

Question 9Measurement, Units and Scientific Method

Which change would most improve the reliability of an experiment measuring the extension of a spring?

  1. Record all readings to the nearest whole centimetre
  2. Repeat the measurements and average the results Correct answer.
  3. Draw the graph in pencil
  4. Use a heavier load on the spring

Explanation

Reliability concerns how consistent results are when the experiment is repeated, so taking several readings and averaging them reduces the influence of random error. Changing the load alters the quantity being tested, and rounding readings more coarsely reduces precision rather than improving reliability.

Question 10Measurement, Units and Scientific Method

A length of 3.5 km is equal to how many metres?

  1. 350 m
  2. 0.0035 m
  3. 3500 m Correct answer.
  4. 35 000 m

Explanation

The prefix kilo means one thousand, so one kilometre contains 1000 metres. Multiplying 3.5 by 1000 shifts the decimal point three places to the right, giving 3500 m.

Question 11Measurement, Units and Scientific Method

A student measures the mass of a stone as 45.0 g and its volume as 15.0 cm³. What is the density of the stone?

  1. 0.33 g/cm³
  2. 30.0 g/cm³
  3. 3.00 g/cm³ Correct answer.
  4. 675 g/cm³

Explanation

Density is mass divided by volume, so 45.0 g ÷ 15.0 cm³ = 3.00 g/cm³. The units confirm this, since grams divided by cubic centimetres give grams per cubic centimetre.

Question 12Measurement, Units and Scientific Method

The diameter of a small sphere is measured with a micrometer screw gauge reading 4.87 mm, with an uncertainty of ±0.01 mm. Which statement about this measurement is correct?

  1. The reading should be rounded to 5 mm
  2. The percentage uncertainty is about 0.2% Correct answer.
  3. The percentage uncertainty is about 2%
  4. The uncertainty is larger than the reading

Explanation

Percentage uncertainty equals the absolute uncertainty divided by the measured value, multiplied by 100. Here 0.01 ÷ 4.87 × 100 is approximately 0.2%, which is small because the reading is much larger than the uncertainty.

Question 13Measurement, Units and Scientific Method

A car travels 150 m in 12 s. What is its average speed?

  1. 162 m/s
  2. 0.08 m/s
  3. 12.5 m/s Correct answer.
  4. 1800 m/s

Explanation

Average speed is distance divided by time, so 150 m ÷ 12 s = 12.5 m/s. Checking the units confirms the result, because metres divided by seconds give metres per second.

Question 14Measurement, Units and Scientific Method

A student plots a graph of extension against load for a rubber band and finds that the line curves. What does this show about the relationship?

  1. Extension decreases as load increases
  2. Extension is independent of load
  3. Extension is directly proportional to load
  4. Extension increases at a decreasing rate as load increases Correct answer.

Explanation

A straight line through the origin would show direct proportionality, but a curve that flattens shows that equal increases in load produce smaller and smaller increases in extension. The gradient is falling, so the extension grows at a decreasing rate.

Question 15Measurement, Units and Scientific Method

A quantity is measured as 6.4 ± 0.2 cm. Which range contains the true value?

  1. 6.0 cm to 6.8 cm
  2. 6.4 cm to 6.6 cm
  3. 6.2 cm to 6.6 cm Correct answer.
  4. 6.2 cm to 6.4 cm

Explanation

The uncertainty of ±0.2 cm means the true value may lie 0.2 cm below or above the measured value. Subtracting and adding gives 6.4 − 0.2 = 6.2 cm and 6.4 + 0.2 = 6.6 cm, so the range is 6.2 cm to 6.6 cm.

Question 16Measurement, Units and Scientific Method

Two students measure the same wire. Student A records 1.24 mm and Student B records 1.31 mm. Which statement about these results is most reasonable?

  1. The average of the two readings is certainly the true value
  2. The larger reading is always the more accurate one
  3. Both results must be wrong because they differ
  4. The difference suggests random error or a systematic difference between the instruments Correct answer.

Explanation

Different readings for the same quantity can arise from random variation, from parallax or zero errors, or from using instruments of different resolution. Disagreement does not prove both are wrong, and averaging two values does not guarantee accuracy.

Question 17Mechanics: Forces, Motion and Energy

A box is pushed with a constant force of 20 N across a horizontal floor for 3.0 m. How much work is done by the push?

  1. 6.7 J
  2. 60 J Correct answer.
  3. 0 J
  4. 23 J

Explanation

Work equals force multiplied by the distance moved along the line of the force, so 20 N times 3.0 m gives 60 J. The force and the motion are in the same direction, so the full product is used.

Question 18Mechanics: Forces, Motion and Energy

What is the unit of force in the SI system?

  1. Watt
  2. Joule
  3. Newton Correct answer.
  4. Pascal

Explanation

Force is measured in newtons, where one newton is the force giving a 1 kg mass an acceleration of 1 m/s². The other listed units measure energy, power and pressure.

Question 19Mechanics: Forces, Motion and Energy

A car travels 120 m in 8.0 s at a steady speed. What is its speed?

  1. 9.6 m/s
  2. 15 m/s Correct answer.
  3. 0.067 m/s
  4. 960 m/s

Explanation

Speed is distance divided by time, so 120 m divided by 8.0 s equals 15 m/s. A steady speed means this single value describes the whole journey.

Question 20Mechanics: Forces, Motion and Energy

Which statement describes Newton's first law of motion?

  1. Every action has an equal and opposite reaction.
  2. An object stays at rest or moves at constant velocity unless a resultant force acts on it. Correct answer.
  3. Force equals mass times acceleration.
  4. The total momentum of a system stays constant.

Explanation

Newton's first law says a body keeps its state of rest or uniform motion in a straight line unless a resultant external force acts. It introduces the idea of inertia, the resistance to change in motion.

Question 21Mechanics: Forces, Motion and Energy

Which form of energy is stored in a stretched rubber band?

  1. Chemical energy
  2. Elastic potential energy Correct answer.
  3. Kinetic energy
  4. Thermal energy

Explanation

Stretching a rubber band does work against its internal restoring forces, storing elastic potential energy. This energy is released when the band is allowed to return to its original shape.

Question 22Mechanics: Forces, Motion and Energy

On the Moon the gravitational field strength is about 1.6 N/kg. What is the weight of a 10 kg object there?

  1. 100 N
  2. 10 N
  3. 16 N Correct answer.
  4. 1.6 N

Explanation

Weight equals mass times gravitational field strength, so 10 kg times 1.6 N/kg gives 16 N. Mass stays the same everywhere, but weight depends on the local field strength.

Question 23Mechanics: Forces, Motion and Energy

A runner completes a 400 m lap of a track and returns to the start. Which quantity is zero for the whole run?

  1. Time taken
  2. Average speed
  3. Distance travelled
  4. Displacement Correct answer.

Explanation

Displacement is the straight-line change in position from start to finish. Returning to the starting point means the start and finish coincide, so displacement is zero even though the path length is 400 m.

Question 24Mechanics: Forces, Motion and Energy

A force of 12 N acts on a 3.0 kg trolley on a frictionless surface. What is the acceleration?

  1. 9.0 m/s²
  2. 0.25 m/s²
  3. 36 m/s²
  4. 4.0 m/s² Correct answer.

Explanation

Newton's second law gives acceleration as force divided by mass, so 12 N divided by 3.0 kg is 4.0 m/s². The trolley accelerates in the direction of the applied force.

Question 25Mechanics: Forces, Motion and Energy

A ball is thrown straight up and rises to its highest point. At that highest point, what is true of its velocity and acceleration?

  1. Velocity is maximum and acceleration is zero.
  2. Velocity is zero and acceleration is directed downwards. Correct answer.
  3. Velocity is directed upwards and acceleration is zero.
  4. Both velocity and acceleration are zero.

Explanation

At the top the ball momentarily stops, so its velocity is zero. Gravity still acts on it, so the acceleration remains about 9.8 m/s² downwards throughout the flight.

Question 26Mechanics: Forces, Motion and Energy

A 50 kg crate is lifted vertically through 2.0 m at constant speed. Taking g as 10 N/kg, how much gravitational potential energy does it gain?

  1. 250 J
  2. 500 J
  3. 100 J
  4. 1000 J Correct answer.

Explanation

The gain in gravitational potential energy equals mass times field strength times height, so 50 kg times 10 N/kg times 2.0 m gives 1000 J. Lifting at constant speed means the work done goes entirely into potential energy.

Question 27Mechanics: Forces, Motion and Energy

A force of 30 N is applied at 60° to the horizontal to drag a box along the floor. What is the horizontal component of the force?

  1. 60 N
  2. 15 N Correct answer.
  3. 30 N
  4. 26 N

Explanation

The horizontal component is found with the cosine of the angle to the horizontal, so 30 N times cos 60° equals 30 times 0.5, which is 15 N. The vertical component would use the sine of the same angle.

Question 28Mechanics: Forces, Motion and Energy

Two forces act on a point: 6 N to the east and 8 N to the north. What is the magnitude of the resultant force?

  1. 14 N
  2. 48 N
  3. 10 N Correct answer.
  4. 2 N

Explanation

Perpendicular forces combine by vector addition, so the resultant magnitude is the square root of 6² plus 8², that is the square root of 100, which is 10 N. The two forces do not simply add because they act at right angles.

Question 29Mechanics: Forces, Motion and Energy

A skydiver falls at terminal velocity. What is true of the forces acting?

  1. No forces act on the skydiver at all.
  2. Air resistance is greater than weight and the skydiver slows down.
  3. Weight is greater than air resistance and the skydiver speeds up.
  4. Weight and air resistance are equal, so the resultant force is zero. Correct answer.

Explanation

Terminal velocity is reached when the upward air resistance grows to equal the downward weight. The resultant force is then zero, so by Newton's first law the velocity stays constant.

Question 30Mechanics: Forces, Motion and Energy

A machine lifts a 200 N load through 3.0 m in 5.0 s. What is its useful output power?

  1. 600 W
  2. 120 W Correct answer.
  3. 3000 W
  4. 40 W

Explanation

Useful work done is force times distance, 200 N times 3.0 m equals 600 J. Power is work divided by time, so 600 J divided by 5.0 s gives 120 W.

Question 31Mechanics: Forces, Motion and Energy

A lever is used to lift a load. The effort arm is 1.2 m from the pivot and the load arm is 0.30 m. What is the mechanical advantage?

  1. 4.0 Correct answer.
  2. 0.25
  3. 1.5
  4. 0.36

Explanation

For an ideal lever the mechanical advantage equals effort arm divided by load arm, so 1.2 m divided by 0.30 m gives 4.0. The lever multiplies the effort force by this factor.

Question 32Mechanics: Forces, Motion and Energy

Which statement best explains why a moving car's brakes become hot when stopping it?

  1. Kinetic energy is transferred to thermal energy by friction. Correct answer.
  2. Thermal energy is converted into kinetic energy.
  3. Chemical energy in the brakes is released by burning.
  4. The car's mass is converted into heat.

Explanation

Braking transfers the car's kinetic energy store to the thermal energy store of the brakes through friction. Energy is conserved overall, but the useful kinetic energy becomes spread-out thermal energy.

Question 33Mechanics: Forces, Motion and Energy

A constant force of 40 N acts on a 5.0 kg object initially at rest for 2.0 s. What is the object's final velocity?

  1. 80 m/s
  2. 4.0 m/s
  3. 8.0 m/s
  4. 16 m/s Correct answer.

Explanation

Acceleration is force divided by mass, 40 N divided by 5.0 kg, giving 8.0 m/s². Using velocity equals acceleration times time, 8.0 m/s² times 2.0 s gives 16 m/s.

Question 34Mechanics: Forces, Motion and Energy

A box of weight 100 N rests on a horizontal floor. The maximum static friction is 35 N. A horizontal push of 25 N is applied and the box stays still. What is the friction force on the box?

  1. 35 N
  2. 10 N
  3. 25 N Correct answer.
  4. 0 N

Explanation

While the box remains stationary, static friction adjusts to balance the applied force exactly. A 25 N push is met by 25 N of friction, which is below the 35 N maximum.

Question 35Mechanics: Forces, Motion and Energy

A ball of mass 0.20 kg hits a wall at 6.0 m/s and rebounds at 4.0 m/s along the same line. What is the magnitude of the change in momentum?

  1. 2.0 kg m/s Correct answer.
  2. 1.2 kg m/s
  3. 0.40 kg m/s
  4. 0.80 kg m/s

Explanation

Momentum change must account for the reversal of direction. Taking the initial direction as positive, the change is 0.20 times negative 4.0 minus 0.20 times 6.0, giving magnitude 2.0 kg m/s.

Question 36Mechanics: Forces, Motion and Energy

A 2.0 kg ball moving at 3.0 m/s collides head-on with a stationary 1.0 kg ball, and they stick together. What is their common velocity after the collision?

  1. 6.0 m/s
  2. 2.0 m/s Correct answer.
  3. 1.5 m/s
  4. 3.0 m/s

Explanation

Momentum is conserved in the collision. Initial momentum is 2.0 kg times 3.0 m/s, which is 6.0 kg m/s, and dividing by the combined mass of 3.0 kg gives 2.0 m/s.

Question 37Mechanics: Forces, Motion and Energy

A block slides down a frictionless slope of height 1.8 m. Taking g as 10 m/s², what is its speed at the bottom?

  1. 6.0 m/s Correct answer.
  2. 3.0 m/s
  3. 18 m/s
  4. 36 m/s

Explanation

Loss of gravitational potential energy equals gain in kinetic energy, so mass times g times height equals half mass times speed squared. The mass cancels, and the speed is the square root of 2 times 10 times 1.8, which is 6.0 m/s.

Question 38Mechanics: Forces, Motion and Energy

A uniform beam is pivoted at its centre. A 6.0 N weight hangs 0.40 m to the left of the pivot. Where must a 4.0 N weight be placed on the right to balance the beam?

  1. 0.27 m from the pivot
  2. 1.5 m from the pivot
  3. 0.60 m from the pivot Correct answer.
  4. 0.40 m from the pivot

Explanation

For balance the clockwise and anticlockwise moments about the pivot must be equal. The left moment is 6.0 N times 0.40 m, which is 2.4 N m, so the right distance is 2.4 divided by 4.0 N, giving 0.60 m.

Question 39Mechanics: Forces, Motion and Energy

A spring obeys Hooke's law. When a 6.0 N force stretches it by 0.030 m, what is its spring constant?

  1. 200 N/m Correct answer.
  2. 0.18 N/m
  3. 180 N/m
  4. 5.0 N/m

Explanation

Hooke's law states force equals spring constant times extension, so the constant is force divided by extension. Dividing 6.0 N by 0.030 m gives 200 N/m.

Question 40Mechanics: Forces, Motion and Energy

A vehicle of mass 800 kg travelling at 15 m/s is brought to rest in 4.0 s. What is the average braking force?

  1. 3000 N Correct answer.
  2. 12000 N
  3. 200 N
  4. 4800 N

Explanation

The deceleration is the change in speed divided by time, 15 m/s divided by 4.0 s, giving 3.75 m/s². Force is mass times acceleration, so 800 kg times 3.75 m/s² gives 3000 N.

Question 41Mechanics: Forces, Motion and Energy

Which of the following is a scalar quantity?

  1. Displacement
  2. Acceleration
  3. Velocity
  4. Speed Correct answer.

Explanation

A scalar has magnitude only and no direction. Speed tells how fast something moves without stating a direction, so it is a scalar. Displacement, velocity and acceleration all require a stated direction, making them vectors.

Question 42Mechanics: Forces, Motion and Energy

A car travels 150 m in 10 s. What is its average speed?

  1. 1500 m/s
  2. 1.5 m/s
  3. 15 m/s Correct answer.
  4. 150 m/s

Explanation

Average speed equals total distance divided by total time. Here 150 m divided by 10 s gives 15 m/s. The average speed does not depend on whether the car moved at a steady rate.

Question 43Mechanics: Forces, Motion and Energy

Which statement describes the force that keeps a satellite moving in a circular orbit around a planet?

  1. A force acting backwards along the path, slowing the satellite down
  2. A force acting away from the planet, balancing the satellite's weight
  3. A force acting along the direction of motion, speeding the satellite up
  4. A force acting towards the centre of the orbit, changing only the direction of motion Correct answer.

Explanation

Circular motion needs a resultant force directed towards the centre of the circle, here provided by gravity. Because this force is always perpendicular to the velocity, it changes direction of motion but not speed. Work done by a perpendicular force is zero, so kinetic energy stays constant.

Question 44Mechanics: Forces, Motion and Energy

An object is dropped from rest and falls freely for 3.0 s. Taking g as 10 m/s² and ignoring air resistance, how far has it fallen?

  1. 45 m Correct answer.
  2. 30 m
  3. 15 m
  4. 90 m

Explanation

For motion from rest under constant acceleration, distance equals half the acceleration multiplied by the time squared. Substituting gives 0.5 × 10 × 3.0² = 45 m. The speed reached, 30 m/s, is not the same as the distance travelled.

Question 45Mechanics: Forces, Motion and Energy

A box is pushed across a rough floor at constant velocity by a horizontal force of 18 N. What is the size of the friction force acting on the box?

  1. 0 N
  2. Less than 18 N
  3. More than 18 N
  4. 18 N Correct answer.

Explanation

Constant velocity means the resultant force on the box is zero, so the forces balance. The friction force must therefore equal the 18 N push but act in the opposite direction. If friction were smaller or larger, the box would speed up or slow down.

Question 46Mechanics: Forces, Motion and Energy

A spring is stretched by 0.20 m when a force of 10 N is applied. What extra force is needed to stretch it a further 0.10 m, assuming Hooke's law is obeyed?

  1. 20 N
  2. 10 N
  3. 15 N
  4. 5 N Correct answer.

Explanation

Hooke's law states that extension is proportional to force, so the spring constant is 10 N ÷ 0.20 m = 50 N/m. A further 0.10 m of extension needs 50 × 0.10 = 5 N extra. The total force at 0.30 m extension is 15 N, but the question asks for the extra force.

Question 47Mechanics: Forces, Motion and Energy

A man of mass 70 kg climbs a flight of stairs of vertical height 4.0 m in 8.0 s. Taking g as 10 N/kg, what is his average useful power output?

  1. 350 W Correct answer.
  2. 2800 W
  3. 28 W
  4. 3500 W

Explanation

Useful work done equals weight times vertical height: 700 N × 4.0 m = 2800 J. Power is work divided by time, giving 2800 J ÷ 8.0 s = 350 W. Only the vertical height matters, not the length of the staircase.

Question 48Mechanics: Forces, Motion and Energy

A moving trolley collides with a stationary trolley and they move off together. Which statement describes the total momentum of the two trolleys?

  1. It stays the same because no external resultant force acts on the system Correct answer.
  2. It increases because the second trolley begins to move
  3. It decreases because some momentum is converted into kinetic energy
  4. It becomes zero because the trolleys stick together

Explanation

Momentum is conserved in a collision when no external resultant force acts on the system. The total momentum before the collision equals the total momentum after it, even though kinetic energy is lost. Sticking together changes the distribution of momentum, not the total.

Question 49Mechanics: Forces, Motion and Energy

A force of 25 N acts on a point at 30° above the horizontal. What is the vertical component of the force?

  1. 12.5 N Correct answer.
  2. 43.3 N
  3. 25 N
  4. 21.7 N

Explanation

The vertical component equals the force multiplied by the sine of the angle to the horizontal. Here 25 × sin 30° = 25 × 0.50 = 12.5 N. The horizontal component uses cosine and is about 21.7 N.

Question 50Mechanics: Forces, Motion and Energy

A 0.50 kg ball moving at 8.0 m/s is brought to rest by a constant force in 0.40 s. What is the magnitude of the force?

  1. 10 N Correct answer.
  2. 1.0 N
  3. 16 N
  4. 4.0 N

Explanation

The change in momentum is 0.50 × 8.0 = 4.0 kg m/s. Force equals change in momentum divided by time, giving 4.0 ÷ 0.40 = 10 N. Equivalently, the deceleration is 20 m/s² and 0.50 × 20 = 10 N.