Mechanics — Variant 3
A Level Mathematics · 9709/43 · Oct/Nov 2021
Questions
5 of 6 questions shown here, checked against the paper. The others are in the PDF above — they contain diagrams or maths we could not yet verify, and we would rather show you the original than a transcription we are not sure of.
1
A metal post is driven vertically into the ground by dropping a heavy object onto it from above. The mass of the object is kg and the mass of the post is kg (see diagram). The object hits the post with speed and remains in contact with it after the impact.
1(a)
[2]
Calculate the speed with which the combined post and object moves immediately after the impact.
1(b)
[3]
There is a constant force resisting the motion of magnitude N. Calculate the distance the post is driven into the ground.
2
A particle of mass kg is suspended in equilibrium by two light inextensible strings which make angles of and above the horizontal.
2(a)
[1]
Draw a diagram showing the forces acting on the particle.
2(b)
[6]
Find the tensions in the strings.
3
A ball of mass kg is released from rest at a point m above horizontal ground. When the ball hits the ground it instantaneously loses J of kinetic energy and starts to move upwards.
3(a)
[3]
Use an energy method to find the greatest height that the ball reaches after hitting the ground.
3(b)
[3]
Find the total time taken, from the initial release of the ball until it reaches this greatest height.
4
A car of mass kg is moving on a straight road against a constant force of N resisting the motion.
4(a)
The car moves along a horizontal section of the road at a constant speed of .
4(a)(i)
[2]
Calculate the work done against the resisting force during the first seconds.
4(a)(ii)
[2]
Calculate, in kW, the power developed by the engine of the car.
4(a)(iii)
[3]
Given that this power is suddenly increased by kW, find the instantaneous acceleration of the car.
4(b)
[2]
The car now travels at a constant speed of up a section of the road inclined at to the horizontal, with the engine working at kW. Find the value of .
5
A particle moves in a straight line, starting from rest at a point on the line. At time s after leaving the acceleration of is , where is a positive constant, and the displacement from is m. The velocity of is when .
5(a)
[5]
Show that .
5(b)
[3]
Find the speed of at the instant that it returns to .
5(c)
[3]
Find the maximum displacement of the particle from .
Published by Cambridge Assessment International Education. Reproduced for study use.