Further Mechanics

Question 0

What is impulse?

Answer 0

The change in momentum, in order to achieve a change in momentum, a resultant force must act on the object.

Question 1

Talk about momentum, units and which quantaty

Answer 1

(kgms^-1) (Ns) Vector quantity

Question 2

Conservation of momentum

Answer 2

In any collision in which no external forces act, the total momentum remains constant.

Question 3

What are elastic and inelastic collisions?

Answer 3

Elastic Collisions: the total kinetic energy is conserved
Inelastic Collisions: When ke is not conserved, the missing energy has become some other form, such as thermal energy. Normall happens when object stick together,

Question 4

What are oblique (glancing) impacts?

Answer 4

When collisions do not take place along a straight line.

Question 5

What is angular velocity

Answer 5

the speed of an object moving in a circle by its speed around a circle. v=2pieR/T given by w

Question 6

Angular displacement,

Answer 6

change in theta that the object goes through as it moves around the circular path. Theta measured in radians

Question 7

What is centripetal acceleration

Answer 7

When an object moves in a circular path it is changing its direction and therefore it is accelerating. a=v^/r

Question 8

What is centripetal force

Answer 8

a body moving in a circular path is accelerating, so there must be a resultant force acting on it. This acts towards the centre of the circle. F=mv^2/r

Question 9

derive ek=p^2/2m

Answer 9

p^2=m^2m^2 – p^2/2m = mv^2/2 = Ek => ek = p^2/2m

Question 10

derive a=v^2/r and a=rw^2

Answer 10

v=wr t=2pie/w a=(wr)^2/r = w^2r^2 /r = w^2r

Question 11

Explain something about centripetal force and circular motion

Answer 11

Resultant force is required to produce and maintain circular motion