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A barge of mass 2×105 kg is being towed, with a force of 2.5 × 10° N,
A railway engine of mass 5000 kg is moving at 0.25 ms when it strikes the buffers in a siding. Given that the engine is brought to rest in 0.4 s, find the force, assumed constant, exerted on the engine by the buffers.
A water-skier of mass 80 kg is towed over a straight 100-metre run of water. The tension in the horizontal towline is constant and of magnitude 300 N. The resistance to motion of the skier has magnitude 140 N. Given that the skier takes 6.8 seconds to complete the run, calculate her speed at the start of the run.
A particle of mass 5 kg is pulled, with constant speed, along a rough surface by a horizontal force of magnitude 45 N. Calculate the magnitude of the frictional force. Assuming that this force remains constant, calculate the acceleration of the particle when the magnitude of the horizontal force is increased to 55 N.
A boy is pushing, horizontally, a box of old newspapers of mass 8 kg along a straight path, against a frictional force of 16 N. Calculate the force with which the boy is pushing when he is moving. (a) with constant speed, (b) with a constant acceleration of 1.2 ms-2.
A student is dragging a luggage trunk of mass 85 kg along a corridor with an acceleration of 0.18 ms2. The horizontal force the student exerts is 180 N. Find the frictional force between the floor and the trunk.
A car of mass 1200 kg is moving with a constant speed of 20 m s in a horizontal straight line, against a resisting force of 300 N. What driving force is being provided to sustain this motion? The driver speeds up uniformly over the next 30s to reach a speed of 30 ms. Assuming that the resisting force remains at 300 N, calculate the extra driving force produced.
A motorcyclist moves with an acceleration of 5 ms^-2 along a horizontal road against a total resistance of 120 N. The total mass of the rider and the motorcycle is 400 kg. Find the driving force provided by the engine.
A boy is pushing one side of a box, of mass m kg, with a force of 25 N. His sister is pushing from the opposite side of the box with a force of 13 N. The box does not move. Given that the frictional force resisting the motion has magnitude 3m N, calculate the value of m. The boy now pushes with an increased force of 35 N. Assuming that the frictional force remains as before, show that the box accelerates at 2.5 m s2.
Three men are trying to move a skip. Two of the men are pushing horizontally with forces of magnitude 120 N and 150 N and one man is pulling with a horizontal force of magnitude X N.
