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Grade 9 · Higher · free GCSE maths worksheet

Calculus in kinematics

Exam boards: Edexcel IGCSE

Velocity and acceleration by differentiating displacement, and greatest values.

10 original questions, 34 marks. Type your answers below for an instant mark and a score, or print the worksheet, mark it with the answers sheet, and use the solutions to see every step written out by hand.

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How to do it

  1. Velocity is the gradient of displacement: v = ds/dt, so differentiate s
  2. Acceleration is the gradient of velocity: a = dv/dt, so differentiate again
  3. For a value at a time, substitute t into the right expression (s, v or a)
  4. At rest means v = 0. Back at O means s = 0. Greatest value: set the derivative to 0
  5. Units: s in m, v in m/s, a in m/s^2. A negative v or a just means the opposite direction

Watch out: Substitute the time into v or a, not into s, and remember acceleration needs two differentiations, not one.

Worked example

A particle moves along a straight line through a fixed point O.

The displacement, s metres, of the particle from O at time t seconds is given by

s = t3 − 6t2 + 5t   for 0 ≤ t ≤ 5

  1. Find an expression for the velocity, v m/s, of the particle at time t seconds.
  2. Find the velocity of the particle when t = 3.
  3. Find the acceleration of the particle when t = 1.

a) v = dsdt, differentiate each term

v=3t2 - 12t + 5

v = 3t2 - 12t + 5

b) put t = 3 into v

v=3 × 32 - 12 × 3 + 5
=27 - 36 + 5

v = -4 m/s

c) a = dvdt, differentiate v

a=6t - 12
a=6 × 1 - 12

a = -6 m/s2

The questions

1

A particle moves along a straight line. At time t seconds its displacement, s metres, from a fixed point O is given by

s = 3t2 + 4t

  1. Find an expression for the velocity, v m/s, of the particle at time t seconds.
  2. Find the velocity of the particle when t = 2.
2 marks
Show answer
a) 6t + 4 b) 16
2

A particle moves along a straight line. At time t seconds its velocity, v m/s, is given by

v = 12t − 2t2

  1. Find an expression for the acceleration, a m/s2, of the particle at time t seconds.
  2. Find the acceleration of the particle when t = 5.
2 marks
Show answer
a) 12 - 4t b) -8
3

A particle P moves along a straight line through a fixed point O. At time t seconds the displacement, s metres, of P from O is given by

s = t3 − 6t2 + 9t + 2

  1. Find an expression for the velocity, v m/s, of P at time t seconds.
  2. Find an expression for the acceleration, a m/s2, of P at time t seconds.
  3. Find the acceleration of P when t = 4.
4 marks
Show answer
a) 3t2 - 12t + 9 b) 6t - 12 c) 12
4

A particle moves along a straight line. At time t seconds its displacement, s metres, from a fixed point O is given by

s = 2t3 − 15t2 + 24t   for 0 ≤ t ≤ 6

Find the values of t for which the particle is momentarily at rest.

3 marks
Show answer
t = 1 or t = 4
5

A particle P moves along a straight line through a fixed point O. At time t seconds the displacement, s metres, of P from O is given by

s = t3 − 9t2 + 5t   for t ≥ 0

  1. Find an expression for the acceleration, a m/s2, of P at time t seconds.
  2. Find the value of t when the acceleration of P is zero.
3 marks
Show answer
a) 6t - 18 b) t = 3
6

The number of bacteria, N, in a dish t hours after the start of an experiment is given by

N = 400 + 30t2 − t3   for 0 ≤ t ≤ 20

  1. Find an expression for dNdt.
  2. Find the rate at which the number of bacteria is increasing, in bacteria per hour, when t = 2.
3 marks
Show answer
a) 60t - 3t2 b) 108
7

Priya throws a ball straight up into the air. The height, h metres, of the ball above the ground t seconds after it leaves her hand is given by

h = 30t − 5t2

  1. Find the value of t when the ball reaches its greatest height.
  2. Find the greatest height, in metres, that the ball reaches.
4 marks
Show answer
a) t = 3 b) 45
8

A train moves along a straight track. At time t seconds its velocity, v m/s, is given by

v = 24t − 3t2   for 0 ≤ t ≤ 8

  1. Find an expression for the acceleration, a m/s2, of the train at time t seconds.
  2. Find the value of t when the velocity of the train is greatest.
  3. Find the greatest velocity of the train, in m/s.
4 marks
Show answer
a) 24 - 6t b) t = 4 c) 48
9

A particle P moves along a straight line. At time t seconds the displacement, s metres, of P from a fixed point O is given by

s = 6t2 − t3

P starts at O when t = 0 and later returns to O.

  1. Find the value of t when P returns to O.
  2. Find the velocity of P, in m/s, at the instant it returns to O.
4 marks
Show answer
a) t = 6 b) -36
10

A particle moves along a straight line through a fixed point O. At time t seconds the displacement, s metres, of the particle from O is given by

s = 2t3 − 21t2 + 60t   for 0 ≤ t ≤ 6

  1. Find the values of t for which the velocity of the particle is zero.
  2. Find the greatest displacement, in metres, of the particle from O during the 6 seconds.
5 marks
Show answer
a) t = 2 or t = 5 b) 52

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Every question here is original and written by Robinson Tuition. This topic is on the Pearson Edexcel International GCSE (4MA1) and is not examined on the UK GCSE; the grade is our estimate against the Edexcel grade descriptors. This is not an exam-board paper.

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