IB Physics Final Topic 2 #2

A vector has magnitude R and perpendicular components P and Q, as shown in the diagram.
Which row correctly describes the perpendicular components? 

• A
• B
• C
• D

The graph shows how the velocity v of an object moving in a straight line varies over time t = 0 to t = T.
Which graph represents the displacement s of the object in the time t = 0 to t = T ? 

• A
• B
• C
• D

Two markers M₁ and M₂ are set up a vertical distance h apart.
A steel ball is released at time zero from a point a distance x above M₁. The ball reaches M₁ at time t₁ and reaches M₂ at time t₂. The acceleration of the ball is constant. Which expression gives the acceleration of the ball? 

• A
• B
• C
• D

A brick is dislodged from a building and falls vertically under gravity.
Which graph best represents the variation of its height h above the ground with time t if air resistance is negligible? 

• A
• B
• C
• D

A projectile is launched at point O and follows the path OPQRS, as shown. Air resistance may be neglected.
Which statement is true for the projectile when it is at the highest point Q of its path? 

• The horizontal component of the projectile’s acceleration is zero. 
• The horizontal component of the projectile’s velocity is zero. 
• The kinetic energy of the projectile is zero. 
• The momentum of the projectile is zero. 

Which row correctly states whether momentum and kinetic energy are conserved in an inelastic collision in which there are no external forces? 

• A
• B
• C
• D

Two spheres approach each other along the same straight line. Their speeds are u₁ and u₂ before collision. After the collision, the spheres separate with speeds v₁ and v₂ in the directions shown in the image. 
Which equation must be correct if the collision is perfectly elastic? 

• u₁ – u₂ = v₂ + v₁ 
• u₁ – u₂ = v₂ – v₁ 
• u₁ + u₂ = v₂ + v₁ 
• u₁ + u₂ = v₂ – v₁ 

A box of mass 8.0 kg rests on a horizontal, rough surface. A string attached to the box passes over a smooth pulley and supports a 2.0 kg mass at its other end.
When the box is released, a frictional force of 6.0 N acts on it.
What is the acceleration of the box?

• 1.4ms^–2 
• 1.7ms^–2 
• 2.0ms^–2 
• 2.5ms^–2 

Initially, four identical uniform blocks, each of mass m and thickness h, are spread on a table.
How much work is done on the blocks in stacking them on top of one another? 

• 3mgh 
• 6mgh 
• 8mgh 
• 10mgh 

The diagram shows the design of a water wheel which drives a generator to produce electrical energy. The flow rate of the water is 200 kg s^–1. The generator supplies a current of 32 A at a voltage of 230 V.
Ignoring any changes in kinetic energy of the water, what is the efficiency of the system? 

• 14% 
• 16% 
• 22% 
• 47%