Linear Motion
11 Grade 10 General Science questions on Linear Motion, with worked marking schemes. 11 questions are available on this topic in full.
Question 1
5 marksA Madaraka Express train moving at 5 m/s as it leaves a station accelerates uniformly at 0.5 m/s² for 20 s.
(a) Calculate the distance the train covers in the 20 s. (3 marks)
(b) Calculate the average velocity of the train during the 20 s. (2 marks)
(5 marks)
Marking scheme for this question
Create a free account to see itQuestion 2
3 marksA cyclist on a straight road in Nakuru increases her velocity from 4 m/s to 10 m/s in 3 s.
(a) Calculate her acceleration. (2 marks)
(b) Later she applies the brakes and her acceleration becomes −2 m/s². State what this value tells you about her motion. (1 mark)
(3 marks)
Marking scheme for this question
Create a free account to see itQuestion 3
1 markA boda boda rider goes round a roundabout in Eldoret and the speedometer reading stays at 30 km/h throughout. Which statement about the motorcycle's motion is correct?
A. Both speed and velocity are constant
B. Both speed and velocity are changing
C. Velocity stays constant but speed keeps changing
D. Speed is constant but velocity changes
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 4
1 markA matatu starts from rest at a stage and accelerates uniformly at 2 m/s² for 5 s. What is its velocity at the end of the 5 s?
A. 25 m/s
B. 10 m/s
C. 7 m/s
D. 2.5 m/s
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 5
1 markLorry drivers going down a long, steep stretch of road such as the Kikuyu–Mai Mahiu escarpment are advised to engage a low gear. What is the main reason for this advice?
A. To reduce the weight of the lorry on the road surface
B. To make the brakes work harder throughout the descent
C. To increase the acceleration of the lorry down the slope
D. To prevent the speed from increasing too much downhill
(1 mark)
Marking scheme
D. To prevent the speed from increasing too much downhill On a slope, part of the lorry's weight acts down the slope and keeps accelerating it, so a low gear uses the engine to hold the speed down and stop it rising dangerously. Low gear does the opposite of making the brakes work harder: it reduces brake use so the brakes do not overheat and fail.
Question 6
5 marksA lorry travelling at 20 m/s along a level highway brakes and decelerates uniformly at 5 m/s² until it stops.
(a) Calculate the distance the lorry travels while braking. (3 marks)
(b) Explain why the same lorry needs a longer distance to stop when it is going down a steep slope. (2 marks)
(5 marks)
Marking scheme
(a) (3 marks) - v² = u² + 2as (1) - 0 = 20² + 2 × (−5) × s, so 0 = 400 − 10s (1) - s = 40 m (1) (b) (2 marks) - On a downhill slope, a component of the lorry's weight acts along the slope in the direction of motion. (1) - This reduces the net force opposing the motion, so the deceleration is smaller and the lorry travels farther before it stops. (1) (Accept: brakes overheat and become less effective on long descents, reducing deceleration.)
Question 7
1 markIn a demonstration, a coin and a feather are released together inside a long glass tube from which the air has been pumped out. Both reach the bottom of the tube at the same time. What does this show?
A. Without air, all bodies fall with equal acceleration
B. Gravity does not act on bodies inside a vacuum
C. Air resistance increases the weight of falling bodies
D. The feather becomes as heavy as the coin in a vacuum
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 8
1 markDuring a PE lesson, Mutua runs exactly once round a 400 m track and stops at his starting point. Which pair correctly gives the distance he covered and his displacement?
A. Distance 400 m, displacement 400 m
B. Distance 400 m, displacement 0 m
C. Distance 0 m, displacement 400 m
D. Distance 200 m, displacement 0 m
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 9
5 marksAt a construction site in Mombasa, a stone is accidentally dropped from rest from the top of a building. It hits the ground 3 s later. Take g = 10 m/s² and ignore air resistance.
(a) Calculate the velocity of the stone just before it hits the ground. (2 marks)
(b) Calculate the height from which the stone was dropped. (2 marks)
(c) Explain why a stone dropped from a higher floor is more dangerous to a worker below. (1 mark)
(5 marks)
Marking scheme for this question
Create a free account to see itQuestion 10
5 marksWanjiku walks 300 m due east from her home to a shop, then 400 m due north from the shop to a church. The whole journey takes 500 s.
(a) State the total distance she walks. (1 mark)
(b) Calculate the magnitude of her displacement from her home. (2 marks)
(c) Calculate her average speed. (1 mark)
(d) Calculate the magnitude of her average velocity. (1 mark)
(5 marks)
Marking scheme for this question
Create a free account to see itQuestion 11
5 marksGrade 10 learners want to show that a falling object speeds up as it falls because of gravity. They have a tennis ball, a measuring tape, a stopwatch and a stable raised platform with a railing, about 2 m high.
(a) Describe how they could carry out the investigation and state the observation that shows the effect of gravity. (3 marks)
(b) State two safety precautions the learners should observe. (2 marks)
(5 marks)
Marking scheme
(a) (3 marks) Method, any two of the following, 1 mark each (2 marks): - Use the measuring tape to mark several heights, e.g. 0.5 m, 1.0 m, 1.5 m and 2.0 m, and release the ball from rest (without pushing it) from each height. - Time each fall with the stopwatch, starting at release and stopping when the ball hits the ground; repeat each height several times and find the average time. - Calculate the average speed (height / time) for each height. - Keep the same learner releasing the ball and the same learner timing throughout, to reduce timing errors. Observation (1 mark): - The average speed is greater for greater heights (the time does not double when the height doubles), showing the ball gains speed as it falls, i.e. gravity accelerates it. (1) (Accept: the ball bounces higher when dropped from a greater height, showing it hits the ground at a higher speed.) (b) Any two of the following, 1 mark each (2 marks): - Ensure nobody stands or walks below the drop zone; clear and mark off the area. - Use only a light, soft ball, never a heavy or hard object. - Do not lean over or climb on the railing or edge of the platform. - Make sure the platform is stable and the activity is supervised by the teacher. - Have a peer steady the platform while it is in use.
8 more marking schemes are on this page. A free account opens all of them, and lets you build your own paper on the topics you have actually taught, laid out in KNEC format with its full marking scheme.
Create a free account