Topic 1 Mechanics

The acceleration of free fall on the Moon is one-sixth of that on Earth. On Earth it takes time t for a stone to fall from rest a distance of 2 m. What is the time taken for a stone to fall from rest a distance of 2 m on the Moon?

Which graph represents the motion of a car that is travelling along a straight road with a speed that increases uniformly with time?

What is the principle of conservation of momentum?

Water is pumped through a hose-pipe at a rate of 90 kg per minute. It emerges from the hose-pipe horizontally with a speed of 20 m/s. Which force is required from a person holding the hose-pipe to prevent it moving backwards?

Two railway trucks of masses m and 3 m move towards each other in opposite directions with speeds 2v and v respectively. These trucks collide and stick together. What is the speed of the trucks after the collision?

A glider is descending at constant speed at an angle of 15° to the horizontal. The diagram shows the directions of the lift L, air resistance R and weight W acting on the glider. Which vector triangle could represent the forces acting on the glider?

A ball is falling at terminal speed in still air. The forces acting on the ball are upthrust, viscous drag and weight. What is the order of increasing magnitude of these three forces?

A projectile is launched at 45° to the horizontal with initial kinetic energy E. Assuming air resistance to be negligible, what will be the kinetic energy of the projectile when it reaches its highest point?

A pendulum bob is held stationary by a horizontal force H. The three forces acting on the bob are shown in the diagram. The tension in the string of the pendulum is T. The weight of the pendulum bob is W. Which statement is correct?

One object moves directly from P to R. In a shorter time, a second object moves from P to Q to R. Which statement about the two objects is correct for the journey from P to R?

The graph shows how velocity v varies with time t for a bungee jumper. At which point is the bungee jumper momentarily at rest and at which point does she have zero acceleration?

An aeroplane travels at an average speed of 600 km/h on an outward flight and at 400 km/h on the return flight over the same distance. What is the average speed of the whole flight?

An archer draws his bowstring back to position X. The bowstring and arrow are shown. The tension T in the string is also shown. Then he draws the bowstring back further to position Y. The resultant force on the arrow is greater when the arrow is released from position Y. What is the increase in force?

A uniform metre rule of weight 2.0 N is pivoted at the 60 cm mark. A 4.0 N weight is suspended from one end, causing the rule to rotate about the pivot. At the instant when the rule is horizontal, what is the resultant turning moment about the pivot?

The diagram shows a barrel of weight 1.0 × 10^3 N on a frictionless slope inclined at 30o to the horizontal. A force is applied to the barrel to move it up the slope at constant speed. The force is parallel to the slope. What is the work done in moving the barrel a distance of 5.0 m up the slope?

A car travelling on a level road at a steady 20 m/s against a constant resistive force develops a power of 40 kW. What is the magnitude of the resistive force?

Which pair contains one vector and one scalar quantity?

A sphere is released and falls. Its initial acceleration reduces until it eventually begins to travel at constant terminal velocity. Which displacement-time graph best represents the motion of the sphere?

The diagram shows two vectors X and Y. In which vector triangle does the vector Z show the magnitude and direction of vector X – Y?

A stone is thrown upwards from the top of a cliff. After reaching its maximum height, it falls past the cliff-top and into the sea. The graph shows how the vertical velocity v of the stone varies with time t after being thrown upwards. R and S are the magnitudes of the areas of the two triangles. What is the height of the cliff-top above the sea?

A wooden block of mass 0.60 kg is on a rough horizontal surface. A force of 12 N is applied to the block and it accelerates at 4.0 m s^–2. What is the magnitude of the frictional force acting on the block?

A body, initially at rest, explodes into two masses M1 and M2 that move apart with speeds v1 and v2 respectively. What is the ratio V1/V2 ?

The vector diagram shows three coplanar forces acting on an object at P. The magnitude of the resultant of these three forces is 1 N. What is the direction of this resultant?

A trolley runs from P to Q along a track. At Q its potential energy is 50 kJ less than at P. At P, the kinetic energy of the trolley is 5 kJ. Between P and Q the work the trolley does against friction is 10 kJ. What is the kinetic energy of the trolley at Q?

To travel at a constant speed, a car engine provides 24 kW of useful power. The driving force on the car is 600 N. At what speed does it travel?

A tennis ball is thrown horizontally in air from the top of a tall building. If the effect of air resistance is NOT negligible, what happens to the horizontal and vertical components of the ball’s velocity?

An object is thrown with velocity 5.2 m s^–1 vertically upwards on the Moon. The acceleration due to gravity on the Moon is 1.62 m s^–2. What is the time taken for the object to return to its starting point?

The graph shows how the acceleration of an object moving in a straight line varies with time. The object starts from rest. Which graph shows the variation with time of the velocity of the object over the same time interval?

An object of mass 4.0 kg moving with a speed of 3.0 m s^–1 strikes a stationary object in an inelastic collision. Which statement is correct?

The graph shows how the momentum of a motorcycle changes with time. What is the resultant force on the motorcycle?

The diagrams show two ways of hanging the same picture. In both cases, a string is attached to the same points on the picture and looped symmetrically over a nail in a wall. The forces shown are those that act on the nail. In diagram 1, the string loop is shorter than in diagram 2. Which information about the magnitude of the forces is correct?

A weight W hangs from a trolley that runs along a rail. The trolley moves horizontally through a distance p and simultaneously raises the weight through a height q. As a result, the weight moves through a distance r from X to Y. It starts and finishes at rest. How much work is done on the weight during this process?

The engine of a car exerts a force of 600 N in moving the car 1.0 km in 150 seconds. What is the average output power of the engine?

The graph is a load-extension graph for a wire undergoing elastic deformation. How much work is done on the wire to increase the extension from 10 mm to 20 mm?

A radio-controlled toy car travels along a straight line for a time of 15 s. The variation with time t of the velocity v of the car is shown below. What is the average velocity of the toy car for the journey shown by the graph?