FORCE, MASS AND ACCELERATION
3 marks · NormalA car and a bicycle are both acted on by the same unbalanced force. The car’s mass is much greater than the bicycle’s mass. Use the relationship F = m x a to explain, in terms of acceleration, what happens to each vehicle.
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The car will accelerate much less than the bicycle because it has a greater mass for the same force. According to F = m x a, if F is constant, then a = F / m, so a larger mass means a smaller acceleration.
Must show: States car accelerates less, States bicycle accelerates more, Links acceleration to mass as inversely proportional
Also accept: Mentions F = m x a and a = F/m form of equation
Common mistakes: Not relating acceleration to the mass quantitatively
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Marking points
B1 · 1 mark · States the car accelerates less than the bicycle for the same force.
B2 · 1 mark · States the bicycle accelerates more.
B3 · 1 mark · Links acceleration to mass using F = m x a (or a = F/m), e.g. says acceleration is inversely proportional to mass.
Worked solution
The car, having a greater mass than the bicycle, will accelerate less when acted on by the same force. The bicycle has a smaller mass, so will accelerate more. Using F = m × a, keeping F the same, acceleration (a) is inversely proportional to mass (m).