FURTHER MECHANICS

Question 1

How do you convert from radians to degrees?

Answer 1

rad x 180/pi

Question 2

How do you convert from degrees to radians?

Answer 2

deg x pi/180

Question 3

An object is moving in a circle. Explain why it must experience a resultant force

Answer 3

1. When an object moves in a circle, its velocity changes direction.
2. This means the object is accelerating.
3. Therefore, due to Newtons Second Law the object experiences a resultant force.

Question 4

Define Centripetal Force:

Answer 4

The Centripetal force is the resultant force acting towards the centre of a circle for an object moving with circular motion.

Question 5

Define Angular velocity:

Answer 5

The angle an object rotates through per second 𝜔=𝜃/𝑡

Question 6

Why a centripetal force is required for an object in circular motion

Answer 6

The object’s velocity is constantly changing direction, but its magnitude remains constant (speed is constant). The force must therefore not cause a magnitude increase, and so must be perpendicular to velocity, but it is needed as the object is accelerating towards the centre of the circle.

Question 7

Describe apparent weightlessness:

Answer 7

1. Astronauts orbiting the Earth and people in free fall experience weightlessness.
2. This is despite the fact that gravity/ weight is acting on them.
3. This is because they do not experience any normal contact forces.

Question 8

Elastic collision

Answer 8

A collision where the total kinetic energy before the collision is the same as the total kinetic energy after a collision

Question 9

Inelastic collision

Answer 9

A collision where the total kinetic energy after the collision is less than the total kinetic energy before the collision – some kinetic energy is transferred into other form

Question 10

Totally inelastic collision

Answer 10

A collision where the bodies have zero kinetic energy after the collision (eg a piece of bluetac being thrown at the floor)