P2 Revision Booklet

Motion

Harder (Grade B-A*)

Q1.          A car is driven along a straight road. The graph shows how the velocity of the car changes during part of the journey.

(a)     Use the graph to calculate the deceleration of the car between 6 and 9 seconds.
Show clearly how you work out your answer and give the unit.
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Deceleration = .................................................
(3)

(b)     At what time did the car change direction?
.................................. seconds
(1)
(Total 4 marks)

 

Q2.          The distance-time graph represents the motion of a car during a race.

(a)     Describe the motion of the car between point A and point D. You should not carry out any calculations.
          To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words.
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(3)

(b)     Calculate the gradient of the graph between point B and point C. Show clearly how you get your answer.
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gradient = ........................................................................
(3)
(Total 6 marks)
 Q3.          The graph shows how the distance travelled by a car changes with time during a short journey.

(i)      Describe fully the motion of the car during the first two minutes of the journey.
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(3)

(ii)      During the last minute of the journey the velocity of the car changes although the speed remains constant. How is this possible?
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(1)
(Total 4 marks)

 
Q4.          The graph shows the speed of a runner during an indoor 60 metres race.

(a)     Calculate the acceleration of the runner during the first four seconds.
(Show your working.)
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(3)

(b)     How far does the runner travel during the first four seconds?
(Show your working.)
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(3)

(c)     At the finish, a thick wall of rubber foam slows the runner down at a rate of 25 m/s2.
The runner has a mass of 75kg.
Calculate the average force of the rubber foam on the runner.
(Show your working.)
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Answer ......................... newtons (N)
(2)
(Total 8 marks)
Motion-Mark scheme

M1.          (a)     4
allow 1 mark for extracting correct information 12
2
          m/s2
ignore negative sign
1
(b)     9 (s)
1
[4]
 M2.          (a)     Quality of written communication
for correct use of term speed in all correct examples
Q  Q 
1
describes all 3 sections correctly for 2 marks
describes 2 or 1 section correctly for 1 mark
max 2
          A – B constant speed
do not accept pace for speed
          B – C (has accelerated) to a higher (constant) speed
          C – D goes back to original / lower (constant) speed
allow for 1 mark, initial and final (constant) speeds are the same accept velocity for speed
ignore reference to direction

(b)     62.5
allow answer to 2 s.f.
allow 1 mark for drawing a correct triangle or for using two correct pairs of coordinates
allow 1 mark for correct use of y/x
ignore units
3
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 M3.          (i)      first statement must be accelerated
if it just accelerated then decelerates award 2 marks
1
          final statement must be stationary
1
          interim statement decelerates
1

(ii)      direction is changing
1
[4]
M4.          (a)     acceleration = 
          or  
gains 1 mark
do not penalise if both of these present
but ‘change in’ omitted from formula
          but
2.5
gains 2 marks
          unit m/s2 or metres per second squared
                                 or metres per second per second
                                 or ms–*
for 1 mark
3

(b)     evidence of using area under graph or distance average speed × time
or
10 × 4 ×
gains 1 mark
          but
20
gains 2 marks
          units metres / m–2*
for 1 mark
3

(c)     force = mass × acceleration or 75 × 25
gains 1 mark
          but
1875
gains 2 marks
          *NB Correct unit to be credited even if numerical answer wrong or absent.
2
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