IBDP Y1_Revision for Term Test 2

An object accelerates in a direction that is always perpendicular to its motion. What is the effect, if any, of the acceleration on the object’s speed and direction?

• speed changes; direction changes

• speed changes; direction is constant

• speed is constant; direction changes

• speed and direction are constant

A tennis ball of mass 100 g is struck by a tennis racket. The velocity of the ball is changed as shown.

What is the magnitude of the change in momentum of the ball?

• u₁ – u₂ = v₂ + v₁

• u₁ – u₂ = v₂ – v₁

• u₁ + u₂ = v₂ + v₁

• u₁ + u₂ = v₂ – v₁

Which statement about a ball that strikes a tennis racket and rebounds is always correct?

• Total kinetic energy of the ball is conserved.

• Total kinetic energy of the system is conserved.

• Total momentum of the ball is conserved.

• Total momentum of the system is conserved

Which is a statement of the principle of conservation of momentum?

• Momentum is the product of mass and velocity.

• Momentum is conserved only in elastic collisions.

• Momentum is conserved by all bodies in a collision.

• Momentum is conserved provided no external forces act.

A mass at the end of a string is swung in a horizontal circle at increasing speed until the string breaks.

The subsequent path taken by the mass is a

•  line along a radius of the circle.

• horizontal circle.

•  curve in a horizontal plane.

•    curve in a vertical plane.

An object at the end of a wooden rod rotates in a vertical circle at a constant angular velocity. What is correct about the tension in the rod? 

• It is greatest when the object is at the bottom of the circle.

• It is greatest when the object is halfway up the circle. 

• It is greatest when the object is at the top of the circle. 

• It is unchanged throughout the motion.

A ball of mass 0.3 kg is attached to a light, inextensible string. It is rotated in a vertical circle. The length of the string is 0.6 m and the speed of rotation of the ball is 4 m s⁻¹.

What is the tension when the string is horizontal?

• 5 N

• 8 N

• 11 N

• 13 N

• 2

• 4