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13+ · Physics

CE.S-P4 Physics: Forces, Motion and Energy Resources

ISEB CE ISEB CE 13+ Science (Physics) · Calculator allowed · about 90 minutes

Total Marks

Name: _______________________________ Date: ____ / ____ / ______

Answer ALL questions. Show all your working.

A force acting on an object can have different effects on it. For each situation below, state the main effect the force has on the object.

(a)Zara kicks a football that was sitting still on the ground, and it begins to move.(1)

(b)A car travels around a roundabout at a constant speed of 20 mph.(1)

(c)Rohan squeezes a rubber stress ball tightly in his hand.(1)

(d)A cricket ball moving towards a batter is struck by the bat and travels back the way it came, much faster than before.(1)

(Total for Question 1 is 4 marks)

For each situation below, state whether the main force acting is a contact force or a non-contact force.

(a)Two bar magnets pushing apart when their like poles are brought close together, without touching.(1)

(b)The runners of a sledge rubbing against the snow as it slides downhill.(1)

(c)The gravitational pull that keeps the Moon in orbit around the Earth.(1)

(d)A person's hand pushing open a heavy wooden door.(1)

(Total for Question 2 is 4 marks)

Leah is a competitive swimmer. At the start of a race, she crouches down and pushes hard backwards against the wall of the pool with her feet.

(a)State Newton's third law of motion.(1)

(b)Leah pushes backwards on the pool wall with a force of 180 N. Using Newton's third law, state the size and direction of the force the wall exerts on Leah.(2)

(Total for Question 3 is 3 marks)

A gardener buys a bag of compost with a mass of 20 kg. Take gravitational field strength on Earth, g = 10 N/kg.

(a)Define mass, including the unit it is measured in.(1)

(b)Calculate the weight of the bag of compost on Earth. Use the equation: weight = mass x gravitational field strength.(2)

(c)The gravitational field strength on the Moon is about one sixth of the value on Earth. Calculate the weight of the same bag of compost on the Moon.(2)

(Total for Question 4 is 5 marks)

Marcus delivers parcels by bicycle. He cycles a distance of 5.4 km at a constant speed, taking 18 minutes. Use the equation: speed = distance / time.

(a)Convert 18 minutes into seconds.(1)

(b)Calculate Marcus's average speed, giving your answer in m/s.(3)

(Total for Question 5 is 4 marks)

Fatima goes for a training run and her distance from home is recorded to draw a distance-time graph. The graph has three straight-line sections: from 0 s to 240 s, her distance increases steadily from 0 m to 960 m; from 240 s to 360 s, her distance stays constant at 960 m; from 360 s to 480 s, her distance increases steadily from 960 m to 1560 m.

(a)Describe what is happening to Fatima's motion between 240 s and 360 s, and explain how this would appear on the distance-time graph.(2)

(b)Calculate Fatima's speed during the first section of her run (0 s to 240 s).(2)

(c)Calculate Fatima's speed during the final section of her run (360 s to 480 s).(2)

(d)State, with a reason, during which section of the run Fatima was travelling fastest, referring to the shape of the graph.(2)

(Total for Question 6 is 8 marks)

Priya trains on a circular athletics track of length 400 m. She completes 4 laps of the track at a constant speed, taking a total time of 320 s.

(a)Calculate the total distance Priya travels.(2)

(b)Calculate Priya's average speed.(2)

(c)Explain why, even though Priya's speed is constant throughout the run, her velocity is not constant.(2)

(Total for Question 7 is 6 marks)

A spanner is used to tighten a nut. Use the equation: moment = force x perpendicular distance from the pivot.

(a)State the equation for calculating the moment of a force.(1)

(b)A force of 80 N is applied perpendicular to the spanner, at a distance of 0.3 m from the nut. Calculate the moment produced.(2)

(c)State one change that would increase the moment produced, without increasing the size of the force applied.(1)

(Total for Question 8 is 4 marks)

Kwame and Elsie sit on a uniform see-saw that is pivoted at its centre. Kwame has a weight of 350 N and sits 1.8 m from the pivot.

(a)State the principle of moments for a beam that is balanced (in equilibrium) on a pivot.(1)

(b)Calculate Kwame's moment about the pivot.(2)

(c)Elsie has a weight of 450 N and sits on the other side of the pivot so that the see-saw is balanced. Calculate the distance from the pivot at which Elsie must sit.(2)

(Total for Question 9 is 5 marks)

A wheelbarrow is a simple machine used to lift heavy loads. It is an example of a lever, with its wheel acting as the pivot. A gardener uses a wheelbarrow to lift a load of 360 N, positioned 0.3 m from the pivot (the wheel). The gardener applies an effort force at the handles, 0.9 m from the pivot.

(a)Calculate the moment of the load about the pivot.(2)

(b)Calculate the minimum effort force needed at the handles to lift the load.(2)

(c)Explain, using the idea of moments, why using the wheelbarrow makes the load easier to lift than carrying it directly.(2)

(Total for Question 10 is 6 marks)

For each situation below, name the main energy store involved.

(a)A spring that has been compressed inside a toy popgun, ready to be released.(1)

(b)A hot water bottle that has just been filled with boiling water.(1)

(c)A skateboarder standing still at the top of a ramp, about to roll down.(1)

(d)The wax and wick of a lit candle.(1)

(Total for Question 11 is 4 marks)

A diver of mass 60 kg jumps from a diving board 5 m above the surface of the water, starting from rest. Take g = 10 N/kg.

(a)State the energy store that decreases as the diver falls, and the energy store that increases.(2)

(b)Calculate the loss in gravitational potential energy as the diver falls the full 5 m. Use the equation: gravitational potential energy (GPE) = mass x g x height.(3)

(c)Assuming no energy is transferred to the surroundings as the diver falls, state the kinetic energy of the diver just before she hits the water.(1)

(d)In reality, some energy is transferred to the surroundings as the diver falls. State the form this wasted energy is most likely to take, and explain why the diver's actual kinetic energy just before hitting the water will be slightly less than your answer to (c).(2)

(Total for Question 12 is 8 marks)

The table below shows some of the energy resources used to generate electricity in the UK, and whether each is renewable or non-renewable.
Resource: natural gas - non-renewable; nuclear fuel - non-renewable; wind - renewable; solar - renewable; hydroelectric - renewable.

(a)State what is meant by a 'non-renewable' energy resource.(1)

(b)Using the table, name one renewable energy resource used to generate electricity in the UK, other than wind.(1)

(c)Wind power output depends heavily on the weather, while a gas power station can generate electricity reliably at almost any time. Explain one disadvantage of relying only on wind power to generate the UK's electricity.(2)

(d)State one advantage of using wind power instead of natural gas to generate electricity.(1)

(Total for Question 13 is 5 marks)

A metal cube has sides of length 3 cm and a mass of 121.5 g. The table below shows the density of four metals.
Metal: aluminium - 2.7 g/cm³; titanium - 4.5 g/cm³; zinc - 7.1 g/cm³; iron - 7.9 g/cm^3.

(a)Calculate the volume of the cube.(2)

(b)Calculate the density of the metal, giving your answer with the correct unit. Use the equation: density = mass / volume.(2)

(c)Using the table, identify which metal the cube is most likely to be made from.(1)

(Total for Question 14 is 5 marks)

Priyanka wants to find the density of a small brass ornament with an irregular shape. She has a mass balance, a measuring cylinder, and water.

(a)Describe a method Priyanka could use to measure the volume of the ornament, using a displacement method.(3)

(b)The ornament has a mass of 178 g. The initial volume of water was 50 cm³, and after fully submerging the ornament the new volume was 73 cm^3. Calculate the density of the ornament, giving your answer to 1 decimal place.(3)

(c)State one precaution Priyanka should take to make sure her volume measurement is as accurate as possible.(1)

(Total for Question 15 is 7 marks)

The density of sea water is 1025 kg/m^3. A ship's cargo container has a mass of 2200 kg and a volume of 2.5 m^3.

(a)Calculate the density of the cargo container, in kg/m^3. Use the equation: density = mass / volume.(2)

(b)Convert your answer to part (a) into g/cm^3. (Hint: 1000 kg/m³ = 1 g/cm^3.)(1)

(c)State, with a reason, whether the cargo container will float or sink in sea water.(2)

(Total for Question 16 is 5 marks)

A uniform plank of wood is balanced on a central pivot, like a see-saw. Two children sit together on the left-hand side of the pivot: Aaliyah, who has a weight of 300 N, sits 1.0 m from the pivot, and her younger brother Isaac, who has a weight of 200 N, sits 0.5 m from the pivot. A third child, Freya, sits alone on the right-hand side.

(a)Calculate the total (combined) moment produced by Aaliyah and Isaac about the pivot.(3)

(b)Freya has a weight of 320 N. Calculate the distance from the pivot at which she must sit for the plank to balance.(2)

(Total for Question 17 is 5 marks)

A cyclist's distance from home is recorded every 60 seconds during a ride.
Time (s): 0, 60, 120, 180, 240, 300
Distance (m): 0, 240, 480, 480, 480, 720

(a)Identify the time interval during which the cyclist was stationary.(1)

(b)Calculate the cyclist's speed between 0 s and 120 s.(2)

(c)Calculate the cyclist's speed between 240 s and 300 s.(2)

(d)Without doing the full division, explain how you could tell directly from the numbers in the table that the speeds calculated in (b) and (c) must be equal.(1)

(Total for Question 18 is 6 marks)

A student wants to investigate how the type of surface affects the force of friction acting on a wooden block being pulled across it at a constant speed, using a newton-meter (force meter) attached to the block.

(a)Identify the independent variable in this investigation.(1)

(b)Identify the dependent variable in this investigation.(1)

(c)State one variable that should be controlled (kept the same) to make this a fair test.(1)

(d)Explain why the block should be pulled at a constant speed when taking each reading.(2)

(e)State one way the reliability of the results could be improved.(1)

(Total for Question 19 is 6 marks)

Wind turbines and gas power stations are both used to generate electricity in the UK. Evaluate the use of wind power compared with gas power stations for generating the UK's electricity, considering both their environmental impact and the reliability of their electricity supply.

(Total for Question 20 is 6 marks)

Mark scheme · CE.S-P4 Physics: Forces, Motion and Energy Resources

Question 1

(a) B1 the force changes the ball's speed (it starts the ball moving from rest / speeds it up), oe
(a) Answer: The force changes the ball's speed, making it start moving from rest.
(b) B1 the force changes the car's direction of travel, oe
(b) Answer: The force changes the car's direction of travel.
(c) B1 the force changes the shape (size) of the ball, oe
(c) Answer: The force changes the shape of the ball.
(d) B1 the force changes both the ball's direction and its speed, oe (accept either one named, with the other implied by 'much faster' and 'back the way it came')
(d) Answer: The force changes both the ball's direction (it reverses) and its speed (it speeds up).

Question 2

(a) B1 non-contact (force), cao
(a) Answer: Non-contact force
(b) B1 contact (force), cao
(b) Answer: Contact force
(c) B1 non-contact (force), cao
(c) Answer: Non-contact force
(d) B1 contact (force), cao
(d) Answer: Contact force

Question 3

(a) B1 when one object exerts a force on a second object, the second object exerts an equal and opposite force back on the first object, oe
(a) Answer: When one object exerts a force on a second object, the second object exerts an equal and opposite force back on the first object.
(b) B1 180 N, cao
(b) B1 direction: forwards, away from the wall (in the direction Leah swims / opposite to the direction she pushed), oe
(b) Answer: 180 N, acting forwards, away from the wall.

Question 4

(a) B1 mass is the amount of matter (substance) in an object, measured in kilograms (kg); it does not change with location, oe
(a) Answer: Mass is the amount of matter in an object, measured in kilograms (kg), and does not change with location.
(b) M1 correct substitution, 20 x 10
(b) A1 200 N, cao
(b) Answer: 200 N
(c) M1 their (b) / 6, i.e. 200 / 6
(c) A1 33.3 N, awrt 33 N, ft from (b)
(c) Answer: 33.3 N (about 33 N)

Question 5

(a) B1 1080 s, cao
(a) Answer: 1080 s
(b) M1 convert 5.4 km to metres, 5400 m
(b) M1 speed = distance / time, 5400 / their (a)
(b) A1 5 m/s, cao, ft
(b) Answer: 5 m/s

Question 6

(a) B1 Fatima is stationary (at rest / not moving), oe
(a) B1 because her distance from home is not changing over this time, the graph shows a flat (horizontal) line during this section, oe
(a) Answer: Fatima is at rest; her distance stays at 960 m, so the graph is a flat, horizontal line between 240 s and 360 s.
(b) M1 speed = distance / time = 960 / 240
(b) A1 4 m/s, cao
(b) Answer: 4 m/s
(c) M1 distance travelled = 1560 - 960 (= 600 m), speed = 600 / 120
(c) A1 5 m/s, cao
(c) Answer: 5 m/s
(d) B1 the final section (360 s to 480 s), cao, ft from (b) and (c)
(d) B1 because this section has the steeper gradient (steeper line) on the distance-time graph, and a steeper gradient represents a greater speed, oe
(d) Answer: The final section (360 s to 480 s), because it has the steeper gradient on the graph, which represents the greater speed (5 m/s compared with 4 m/s).

Question 7

(a) M1 4 x 400
(a) A1 1600 m, cao
(a) Answer: 1600 m
(b) M1 speed = their (a) / 320
(b) A1 5 m/s, cao, ft
(b) Answer: 5 m/s
(c) B1 velocity is speed in a stated (given) direction, oe
(c) B1 because the track is circular, Priya's direction of travel is continually changing as she runs, so her velocity keeps changing even though her speed stays the same, oe
(c) Answer: Velocity is speed in a given direction. Because Priya runs around a circular track, her direction keeps changing, so her velocity changes even though her speed stays constant.

Question 8

(a) B1 moment = force x (perpendicular) distance from the pivot, oe
(a) Answer: Moment = force x perpendicular distance from the pivot.
(b) M1 80 x 0.3
(b) A1 24 Nm, cao
(b) Answer: 24 Nm
(c) B1 increase the distance from the pivot at which the force is applied, e.g. use a longer spanner, oe
(c) Answer: Use a longer spanner, increasing the distance from the pivot at which the force is applied.

Question 9

(a) B1 when a beam is balanced, the sum of the clockwise moments about the pivot equals the sum of the anticlockwise moments, oe
(a) Answer: When a beam is balanced, the sum of the clockwise moments about the pivot equals the sum of the anticlockwise moments.
(b) M1 350 x 1.8
(b) A1 630 Nm, cao
(b) Answer: 630 Nm
(c) M1 450 x d = their (b), rearrange to d = their (b) / 450
(c) A1 1.4 m, cao, ft
(c) Answer: 1.4 m

Question 10

(a) M1 360 x 0.3
(a) A1 108 Nm, cao
(a) Answer: 108 Nm
(b) M1 effort = their (a) / 0.9
(b) A1 120 N, cao, ft
(b) Answer: 120 N
(c) B1 the effort force needed (120 N) is much smaller than the weight of the load (360 N), oe, ft
(c) B1 because the effort acts at a greater distance from the pivot than the load does, a smaller force is needed to produce the same moment as the load, oe
(c) Answer: The effort force needed (120 N) is smaller than the load's weight (360 N), because the effort acts further from the pivot than the load, so a smaller force produces the same moment.

Question 11

(a) B1 elastic (potential) energy store, oe
(a) Answer: Elastic (potential) energy store
(b) B1 thermal (internal) energy store, oe
(b) Answer: Thermal (internal) energy store
(c) B1 gravitational potential energy store, oe
(c) Answer: Gravitational potential energy store
(d) B1 chemical energy store, oe
(d) Answer: Chemical energy store

Question 12

(a) B1 gravitational potential energy store decreases, oe
(a) B1 kinetic energy store increases, oe
(a) Answer: The gravitational potential energy store decreases; the kinetic energy store increases.
(b) M1 GPE = mgh
(b) M1 correct substitution, 60 x 10 x 5
(b) A1 3000 J, cao
(b) Answer: 3000 J
(c) B1 3000 J, ft from (b)
(c) Answer: 3000 J
(d) B1 energy is transferred to the surroundings as thermal energy (heat) and sound, mainly due to air resistance acting on the diver, oe
(d) B1 because some of the GPE lost is dissipated to the surroundings rather than being usefully transferred to the diver's kinetic energy store, her actual KE will be less than 3000 J, oe, ft
(d) Answer: Some energy is transferred as heat and sound because of air resistance, so it is dissipated to the surroundings rather than staying as kinetic energy, meaning her actual KE is slightly less than 3000 J.

Question 13

(a) B1 a resource that is used up faster than it can be replaced (it is finite) and will eventually run out, oe
(a) Answer: A resource that is finite and will eventually run out, because it is used up faster than it can be replaced.
(b) B1 solar OR hydroelectric
(b) Answer: Solar (or hydroelectric)
(c) B1 on a day with little or no wind, very little (or no) electricity can be generated by wind turbines, oe
(c) B1 so electricity supply from wind alone may not be able to match demand at all times, unless another resource is used to make up the difference, oe
(c) Answer: On a still day, wind turbines generate very little electricity, so supply from wind alone cannot always match demand unless backed up by another resource.
(d) B1 wind power produces no carbon dioxide (or other polluting gases) while generating electricity, unlike burning natural gas, oe
(d) Answer: Wind power produces no carbon dioxide while generating electricity, unlike burning natural gas.

Question 14

(a) M1 3 x 3 x 3 (or 3³)
(a) A1 27 cm³, cao
(a) Answer: 27 cm³
(b) M1 121.5 / their (a)
(b) A1 4.5 g/cm³, cao, ft
(b) Answer: 4.5 g/cm³
(c) B1 titanium, cao, ft from (b)
(c) Answer: Titanium

Question 15

(a) B1 partly fill the measuring cylinder with water and record the initial volume reading, oe
(a) B1 tie the ornament to a thread and lower it fully into the water, making sure it is completely submerged and not touching the sides or bottom of the cylinder, then record the new (higher) volume reading, oe
(a) B1 calculate the volume of the ornament by subtracting the initial volume reading from the new (final) volume reading, oe
(a) Answer: Record the initial volume of water, fully submerge the ornament (without touching the sides), record the new volume, then subtract the initial reading from the new reading to find the volume of the ornament.
(b) M1 volume of ornament = 73 - 50 (= 23 cm³)
(b) M1 density = mass / volume, 178 / 23
(b) A1 7.7 g/cm³, awrt 7.7
(b) Answer: 7.7 g/cm³
(c) B1 any sensible precaution, e.g. make sure the ornament is fully submerged and not touching the sides/bottom of the cylinder, read the water level at eye level to avoid parallax error, or make sure no air bubbles are trapped on the ornament
(c) Answer: For example, read the water level at eye level to avoid a parallax error.

Question 16

(a) M1 2200 / 2.5
(a) A1 880 kg/m³, cao
(a) Answer: 880 kg/m³
(b) B1 0.88 g/cm³, ft from (a)
(b) Answer: 0.88 g/cm³
(c) B1 float, cao, ft from (a)
(c) B1 because the density of the cargo container (880 kg/m³) is less than the density of sea water (1025 kg/m³), oe
(c) Answer: Float, because its density (880 kg/m³) is less than the density of sea water (1025 kg/m³).

Question 17

(a) M1 Aaliyah's moment = 300 x 1.0 (= 300 Nm)
(a) M1 Isaac's moment = 200 x 0.5 (= 100 Nm)
(a) A1 total moment = 400 Nm, cao (both moments act in the same rotational direction, so they are added together)
(a) Answer: 400 Nm
(b) M1 d = their (a) / 320
(b) A1 1.25 m, cao, ft
(b) Answer: 1.25 m

Question 18

(a) B1 120 s to 240 s, cao
(a) Answer: 120 s to 240 s
(b) M1 480 / 120
(b) A1 4 m/s, cao
(b) Answer: 4 m/s
(c) M1 (720 - 480) / (300 - 240), i.e. 240 / 60
(c) A1 4 m/s, cao
(c) Answer: 4 m/s
(d) B1 both pairs of values simplify to the same ratio of distance to time, 4:1 (480:120 and 240:60 both simplify to 4:1), oe
(d) Answer: 480:120 and 240:60 both simplify to the same ratio, 4:1, so the two speeds must be equal.

Question 19

(a) B1 the type of surface the block is pulled across, oe
(a) Answer: The type of surface the block is pulled across.
(b) B1 the force of friction, measured as the reading on the newton-meter, oe
(b) Answer: The force of friction, shown by the reading on the newton-meter.
(c) B1 any one sensible control variable, e.g. the same wooden block (same mass/weight and same surface area in contact with the surface), or the same newton-meter
(c) Answer: For example, the same wooden block should be used for every surface tested.
(d) B1 when the block moves at a constant speed, the forces acting on it are balanced (the resultant force is zero), oe
(d) B1 so the reading on the newton-meter is then equal in size to the friction force acting on the block, giving an accurate measurement of friction, oe
(d) Answer: At a constant speed the forces on the block are balanced, so the newton-meter reading equals the friction force, giving an accurate measurement.
(e) B1 repeat each reading (for each surface) and calculate a mean value, oe
(e) Answer: Repeat each reading for each surface and calculate a mean value.

Question 20

Level 1 (1-2): A basic, largely one-sided or isolated point is made about wind or gas power, such as simply stating that wind is renewable or that gas produces carbon dioxide, with little or no comparison or linked reasoning.
Level 2 (3-4): Some relevant comparative points are made about both wind and gas power, covering environmental impact and/or reliability of supply, but the evaluation is not fully balanced, the reasoning linking points is not always clear, and there is limited or no overall judgement.
Level 3 (5-6): A clear, well-linked evaluation of both wind and gas power is given, covering environmental impact (carbon dioxide emissions and the use of a finite resource) and reliability of supply (dependence on weather compared with the ability to generate electricity on demand), leading to a justified overall conclusion about which is more appropriate for a reliable, low-carbon UK electricity supply, or that a mixture of both is needed.
Indicative content:
- Wind turbines produce no carbon dioxide (or other polluting gases) while generating electricity, which helps to reduce the UK's contribution to climate change.
- Gas power stations release carbon dioxide (and other pollutant gases) when natural gas is burned, contributing to climate change and air pollution.
- Wind is a renewable resource and will not run out; natural gas is a non-renewable (finite) resource, and reserves will eventually run out.
- Wind power output depends on wind speed and the weather, so it cannot always generate electricity when it is needed, for example almost no electricity is generated on a still day, making supply less reliable and predictable.
- Gas power stations can be started up and have their output controlled (or increased) quickly, so they can reliably match electricity supply to demand at almost any time of day.
- Large-scale electricity storage is limited, so a backup resource such as gas is often still needed to cover times when wind output is low, even in a system with many wind turbines.
- A balanced UK electricity supply is likely to need a mixture of resources: wind power to help reduce carbon dioxide emissions, backed up by a more reliable and controllable resource such as gas for times when renewable output is low.
- A justified conclusion could reasonably favour either resource, or a mixture of the two, depending on whether environmental impact or reliability of supply is given more weight, provided the judgement is supported by points made in the answer.

Physics: Forces, Motion and Energy Resources - Worksheets, Questions and Revision