9709/42 · May/June 2026
Download PDFA car of mass is moving on a straight horizontal road. There is a constant force of magnitude resisting the motion of the car.
Calculate the power developed by the engine of the car when it is moving at a constant speed of .
Given that the power is suddenly increased by , find the instantaneous acceleration of the car.
Two particles, and , of masses and respectively are at rest on a straight smooth horizontal track. Particle is situated from a vertical wall which is fixed at right angles to the track. Particle is projected directly towards with a speed of . In the subsequent motion, collides and coalesces with to form particle . Particle then collides directly with the wall and rebounds. The collision of with the wall reduces the speed of by .
Find the speed of after it rebounds from the wall.
Hence find the time from the instant at which and collide until is once again a distance of from the wall.
Two particles, and , of masses and respectively are attached to the ends of a light inextensible string. The string passes over a small smooth pulley fixed at the end of a rough horizontal plane and to the top of a smooth inclined plane. Particle is held on the horizontal plane, while lies on the inclined plane, which makes an angle of with the horizontal. The string is in the same vertical plane as a line of greatest slope of the inclined plane (see diagram). Particle is released from rest with the string taut. Particle moves down the inclined plane in .

Find the tension in the string.
Find the coefficient of friction between and the horizontal plane.
After has been moving for , the string suddenly breaks. Given that subsequently comes to rest on the horizontal plane, find the work done by the frictional force in bringing to rest. You may assume that does not reach the pulley.
A particle is projected from a point with speed up a line of greatest slope of a rough plane inclined at an angle to the horizontal, where . comes to instantaneous rest at a point on the plane (see diagram). The coefficient of friction between and the plane is .

Using an energy method, show that the distance is .
After coming to instantaneous rest at , the particle slides down the plane. Find the total time from the instant at which is projected from until it returns to .
The points and are at the same vertical height above horizontal ground. A particle is released from rest from . One second later, a particle is projected vertically downwards from with speed . Given that and reach the ground at the same time, find the value of .
A crate of weight is at rest on rough horizontal ground. The crate is pulled at a constant acceleration of along the ground in a straight line by a light rope. The rope is inclined at an angle of to the horizontal, where . The tension in the rope is (see diagram). The coefficient of friction between the crate and the ground is .

Find the value of .
When the crate reaches a point , the rope is removed. The speed of the crate at is . The crate comes to rest at a point . Find the distance .
A particle moves in a straight line. The velocity of at time , where , is given by where and are constants. When the deceleration of is .
Find the value of .
Given that is only at instantaneous rest when , find the distance travelled by in the interval .






