Topic 6 Further mechanics

Question 1

In the sport of curling, two teams of ‘curlers’ take turns sliding polished granite stones across an ice surface towards a circular target marked on the ice.

Stone B is stationary. Stone A travels towards the target and makes a direct hit on stone B. Both stones have mass m.

The collision is elastic. Just before the collision stone A has a velocity v. After the collision stone B moves off with velocity v.

Discuss how the relevant conservation laws apply to this collision. (6)

Answer 1

-Collision takes place on ice so there is minimal friction.
-Momentum is conserved in the collision.
-As momentum of stone A before collision is equal to momentum of stone B after collision.
-Stone A must be at rest after collision.
-All of the kinetic energy from stone A is transferred to stone B.
-Kinetic energy is conserved in an elastic collision.

Question 2

Explain how the apparent weight experienced by the rider would change as they are at different positions of a loop on roller coaster. (6)

Answer 2

-Rider experiences a resultant force acting towards the centre of a circular path.
-This resultant force is constant as the rider has a constant angular velocity/Weight is constant.
-At bottom of the loop push from seat on rider (P) and weight of rider (W) act in the opposite direction, so P must be greater than W here.
-At the top of the loop P and W act in the same direction, so P must be less than W here.
-P is the weight the rider appears to have.
-The rider would feel heavier at bottom of loop/lighter at top of loop.