IB DP Topic 2 Mechanics (SL & HL)

At time t = 0, a body moves from rest with constant acceleration in a straight line.  At time t, the body is distance s from its rest position.
A graph is drawn of s against t², as shown.
Which statement describes the acceleration of the body? 

• It is equal to half the value of the gradient of the graph. 
• It is equal to the value of the gradient of the graph. 
• It is equal to twice the value of the gradient of the graph. 
• It is equal to the reciprocal of the gradient of the graph. 

A lift (elevator) consists of a passenger car supported by a cable which runs over a light, frictionless pulley to a balancing weight. The balancing weight falls as the passenger car rises. 
What is the magnitude of the acceleration of the car when carrying just one passenger and when the pulley is free to rotate? 

• 0.032 ms^–2 
• 0.32 ms^–2 
• 0.6 ms^–2 
• 0.65 ms^–2 

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

Two spheres travel along the same line with velocities u₁ and u₂. They collide and after collision their velocities are v₁ and v₂.  
Which collision is not elastic? 

• A
• B
• C
• D

Tags

NGSS.HS-PS2-2

A wooden block rests on a rough board. The end of the board is then raised until the block slides down the plane of the board at constant velocity v. 
Which row describes the forces acting on the block when sliding with constant velocity? 

• A
• B
• C
• D

Tags

NGSS.HS-PS2-1

A ball of mass m is thrown up to height h in air with an initial velocity v, as shown.
Air resistance is considered negligible. The acceleration of free fall is g. What is the total work done by the gravitational force on the ball during its flight from P to Q? 

• zero
• ½mv²
• mgh
• 2 mgh 

Tags

NGSS.HS-PS2-4

A spring of unextended length 40 mm is suspended from a fixed point. A load of 16 N is applied to the free end of the spring. This causes the spring to extend so that its final length is five times its original length. The spring obeys Hooke’s Law.
What is the energy stored in the spring due to this extension?

• 1.3 J
• 1.6 J
• 2.6 J
• 3.2 J

The diagram shows an arrangement used to find the output power of an electric motor. The wheel attached to the motor’s axle has a circumference of 0.5 m and the belt which passes over it is stationary when the weights have the values shown. 
If the wheel is making 20 revolutions per second, what is the output power of the motor? 

• 300 W
• 500 W
• 600 W
• 700 W

A ball is dropped from rest at time t = 0 on to a horizontal surface from which it rebounds. Which one of the following graphs best shows the variation of speed v of the ball with time t from the time t = 0 to the time that the ball leaves the surface? 

• A
• B
• C
• D

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

Which one of the following is a true statement concerning the vertical component of the velocity and the acceleration of a projectile when it is at its maximum height? 

• A
• B
• C
• D

A block rests on a rough horizontal plane and a force P is applied to the block as shown. 
The normal reaction between the plane and the block is N and the frictional force between the block and the plane is F. The coefficient of static friction between the block and the plane is μS and initially P is zero.
As P is increased in value, which one of the following statements is true concerning the relationship between F, N and μS ? 

• F is always equal to μ_SN
  
• F is always greater than μ_SN 
• F is always less than μ_SN
  
• F can be equal to μ_SN 

Tags

NGSS.HS-PS2-1