Section 1: Motion, forces and energy

Change every value to metres, seconds and kilograms before you substitute. On a graph, read the axes first: the gradient of distance against time is speed; the area under speed against time is distance.

A lesson for this section

Multiple choice, Paper 1 and Paper 2 style

Question 1

A student times 20 complete swings of a pendulum with a stopwatch. The stopwatch reads 31.4 s. What is the period of the pendulum?

Question 2

A student pours water into a measuring cylinder to find its volume. How should she read the scale?

Question 3

A new packet of 500 sheets of printer paper is 4.5 cm thick. What is the thickness of one sheet?

Question 4 · Extended

Which of these quantities is a scalar?

Question 5 · Extended

A drone flies due north at 2.4 m/s relative to the air. A wind carries the air due east at 1.0 m/s. What is the size of the drone's resultant velocity?

Question 6

A train travels 54 km between two stations in 45 minutes. What is its average speed in m/s?

Question 7

The distance-time graph shows a girl's walk to a bus stop. What is her speed during the last part of the walk, from 25 s to 35 s?

Question 8

Which shape on a distance-time graph shows an object that is speeding up?

Question 9 · Extended

A car joining a motorway speeds up from 8.0 m/s to 26 m/s in 6.0 s. What is its acceleration?

Question 10 · Extended

A skydiver falls at a steady terminal velocity before opening her parachute. Which statement explains why her speed is constant?

Question 11

An astronaut's toolkit has a mass of 12 kg. The gravitational field strength on the Moon is 1.6 N/kg. What is the weight of the toolkit on the Moon?

Question 12

A rock sample is brought back from the Moon to the Earth. What happens to its mass and its weight?

Question 13

A stone of mass 41.6 g is lowered into a measuring cylinder. The water level rises from 40.0 cm³ to 56.0 cm³. What is the density of the stone?

Question 14

Water has a density of 1000 kg/m³. Which object floats in water?

Question 15 · Extended

Three liquids that do not mix are poured into a tall jar: cooking oil (920 kg/m³), golden syrup (1400 kg/m³) and water (1000 kg/m³). In what order do they settle, from the top?

Question 16

A cyclist on a flat road has a forward driving force of 180 N. Air resistance on her is 65 N and friction on the tyres is 25 N, both backwards. What is the resultant force on her?

Question 17

A space probe far from any star or planet moves at 3 km/s with its engines switched off. No resultant force acts on it. What happens to its motion?

Question 18 · Extended

A forklift truck of mass 1500 kg accelerates at 0.80 m/s² across a warehouse floor. Friction forces on it total 400 N. What driving force does its motor provide?

Question 19 · Extended

A spring is 12.0 cm long. When a load of 4.8 N hangs from it, it is 15.2 cm long. It is still within its limit of proportionality. What is its spring constant?

Question 20 · Extended

The load-extension graph is for a steel spring. At what load does the spring reach its limit of proportionality?

Question 21 · Extended

A student whirls a rubber bung on a string in a horizontal circle. She pulls harder on the string but keeps the radius of the circle the same. What happens to the bung?

Question 22

A cyclist squeezes the brakes, and the brake pads press on the moving wheel rims. Which statement describes the friction between the pads and the rims?

Question 23

A mechanic pushes on the end of a spanner with a force of 60 N at right angles to the handle, 25 cm from the centre of the nut. What is the moment of the force about the nut?

Question 24

A girl of weight 400 N sits 1.5 m from the pivot of a see-saw. Her brother weighs 500 N. How far from the pivot, on the other side, must he sit for the see-saw to balance?

Question 25 · Extended

A metre rule balances at its centre on a pivot. A 2.0 N weight hangs 40 cm to the left of the pivot and a 3.0 N weight 20 cm to the left of the pivot. What downward force 40 cm to the right of the pivot keeps the rule balanced?

Question 26

A loaded shelf bracket stays perfectly still on a wall. Which statement about the bracket is true?

Question 27

A designer wants a desk lamp that is hard to knock over. Which design is most stable?

Question 28

A student hangs an irregular piece of card from a pin through a small hole. When it is still, she draws a line on the card along a plumb line hung from the pin. What should she do next to find the card's centre of gravity?

Question 29 · Extended

A cricket ball of mass 0.16 kg is bowled at 30 m/s. What is its momentum?

Question 30 · Extended

A footballer kicks a stationary ball of mass 0.45 kg. Her boot is in contact with the ball for 0.012 s and the ball leaves at 24 m/s. What is the average force on the ball?

Question 31 · Extended

A trolley of mass 2.0 kg moving at 3.0 m/s collides with a stationary trolley of mass 1.0 kg. They stick together. What is their speed just after the collision?

Question 32 · Extended

Two ice skaters stand still facing each other and push apart. The girl, of mass 50 kg, moves off at 1.5 m/s. The boy has a mass of 75 kg. At what speed does he move off?

Question 33 · Extended

In a crash, an airbag reduces the force on a driver. Which statement explains why?

Question 34

A child pulls back the rubber band of a toy catapult and lets go, and a foam ball flies forwards. Which energy store empties as the band springs back?

Question 35

An electric kettle heats water. How is energy transferred, and which store does it fill?

Question 36 · Extended

A small car of mass 800 kg travels at 12 m/s. How much energy is in its kinetic store?

Question 37 · Extended

A climber of mass 62 kg climbs a cliff path that rises 350 m. By how much does her gravitational potential energy increase?

Question 38

A ball rolls down a smooth ramp. Friction and air resistance are small enough to ignore. Which statement is correct?

Question 39 · Extended

A Sankey diagram for an electric motor shows 800 J of electrical energy in, 560 J out to the kinetic store of the load, 40 J carried away by sound and one more arrow for the energy that heats the motor. How much energy heats the motor?

Question 40

A shopper pushes a trolley 24 m along an aisle with a steady force of 35 N in the direction of motion. How much work does she do on the trolley?

Question 41

The brakes of a car do 45 kJ of work as they bring the car to a stop on a level road. What happens to the energy in the car's kinetic store?

Question 42

Which power station turns its turbines without boiling water to make steam?

Question 43

An island needs electricity at short notice on calm, cloudy evenings. Which renewable resource can supply it?

Question 44 · Extended

Radiation from the Sun is the main source of energy for most energy resources. Which resource does not get its energy from the Sun?

Question 45 · Extended

An LED desk lamp takes in 12 W of electrical power and gives out 4.2 W of useful light. What is its efficiency?

Question 46

A lift motor does 54 kJ of work raising a lift in 12 s. What is the useful power output of the motor?

Question 47

A student of weight 560 N runs up a flight of stairs 3.5 m high in 4.0 s. What useful power does she develop lifting herself?

Question 48

Two cranes lift identical loads through the same height. Crane X takes 20 s and crane Y takes 40 s. Which statement is correct?

Question 49

A woman of weight 600 N stands on one heel of her shoe. The area of the heel in contact with the floor is 1.5 cm². What pressure does the heel exert on the floor?

Question 50

Why are tractors that work on soft, wet fields fitted with very wide tyres?

Question 51

The wall of a dam is much thicker at the bottom than at the top. Why?

Question 52 · Extended

A diver descends from the surface to a depth of 12 m in sea water of density 1030 kg/m³. By how much does the pressure on her increase?

Theory and practical questions

A cycle ride between two traffic lightsTheory, Core · 8 marks

A cyclist sets off from a red traffic light when it turns green and stops at the next red light. The speed-time graph shows her ride.

(a) Describe her motion between 10 s and 40 s. [1]

(b) Calculate the total distance she travels between the two traffic lights. [3]

m/s

(d) Describe her motion between 40 s and 50 s. [2]

0 words · one point a mark

Railway wagons couplingTheory, Extended · 8 marks

In a freight yard, wagon A of mass 12 000 kg rolls at 2.5 m/s towards wagon B of mass 8000 kg, which is at rest on a level track. The wagons collide and couple together, then move off at the same speed. Friction is small enough to ignore.

(a) Calculate the momentum of wagon A before the collision. [2]

kg m/s

(b) Calculate the speed of the coupled wagons just after the collision. [2]

m/s

(d) The wagons have spring buffers. Explain, in terms of momentum, how the buffers reduce the force between the wagons. [2]

0 words · one point a mark

Choosing a power supply for a townTheory, Core · 7 marks

A town council compares two ways of generating its electricity: a wind farm on nearby hills, and a power station that burns natural gas.

(a) State one advantage of the wind farm compared with the gas power station. [1]

0 words · a sentence

(b) Describe how the gas power station generates electricity from the energy in the gas. [3]

0 words · one point a mark

(d) Suggest one disadvantage of the wind farm. [1]

0 words · a sentence

A car on a test trackTheory, Extended · 10 marks

On a level test track, a car of mass 1200 kg accelerates steadily from rest to 18 m/s in 12 s.

(a) Calculate the acceleration of the car. [2]

m/s²

(b) Calculate the resultant force on the car. [2]

(d) Calculate the average rate at which the car's kinetic store fills during the 12 s. [2]

(e) Explain why the engine must supply energy at a greater rate than your answer to the previous part. [2]

0 words · one point a mark

The average speed of a trolley on a rampAlternative to practical style · 6 marks

A student releases a trolley from rest at the top of a ramp. A metre rule lies along the ramp: the front of the trolley starts level with the 12.0 cm mark, and a finish line is drawn level with the 92.0 cm mark. She times the trolley from release to the finish line with a stopwatch, three times. The table shows her times.

Three timings of the trolley from release to the finish line: 2.46 s, 2.52 s and 2.49 s.
run	time / s
1	2.46
2	2.52
3	2.49

(a) Determine the distance the trolley travels from the start to the finish line, in cm. [1]

(b) Calculate the mean time for the trolley to reach the finish line. [1]

m/s

(d) Explain why the student times the trolley three times and uses the mean. [1]

0 words · a sentence

(e) Suggest one improvement to the way the student measures the time. [1]

0 words · a sentence

Pressure and depth in waterAlternative to practical style · 7 marks

A student lowers a pressure sensor into a tall tank of water and measures the increase in pressure, Δp, above the pressure at the surface for five depths, h. The graph shows her results with a best-fit straight line, drawn from (0, 0) to (0.50 m, 4900 Pa).

(a) What does the graph show about the relationship between Δp and h? [1]

(b) Determine the gradient of the best-fit line. Use the two ends of the line. [2]

Pa/m

kg/m³

(d) Suggest one precaution the student should take to measure the depth accurately. [1]

0 words · a sentence

(e) Suggest one reason why the points do not all lie exactly on the line. [1]

0 words · a sentence