FORCE, MASS AND ACCELERATION
4 marks · NormalA train of mass 2,000 kg leaves a station and accelerates along a straight track.
State the equation that links force, mass, and acceleration. Use scientific symbols.
If the resultant force on the train is 5,000 N, calculate the acceleration of the train.
Explain what would happen to the acceleration if the mass of the train were doubled but the resultant force remained the same.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) F = m × a
(b) 2.5 m/s^2
(c) The acceleration would be halved.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States correct equation using scientific symbols (F = m × a)
M1 (b) · 1 mark · Uses or rearranges F = m × a correctly for acceleration
A1 (b) · 1 mark · Substitutes correct values, calculates acceleration as 2.5 m/s^2 (or 2.50 m/s^2), correct unit (follow-through)
B2 (c) · 1 mark · Explains that doubling the mass halves the acceleration if force is unchanged
Worked solution
a) The equation is F = m × a.
b) Rearranging F = m × a gives a = F / m.
c) If the mass is doubled and the same force is applied, acceleration would be halved, because a ∝ 1/m when F is constant.