P10 - Forces And Motion

Question 1

Equation for momentum?

Answer 1

M = mass * velocity

Question 2

Conservation of momentum equation?

Answer 2

(Mass A * Velocity of A) = - (Mass of B * Velocity of B)

‘-‘ tells you that momentum B is opposite to A, opposite and equal.

Question 3

The longer the impact time….

Answer 3

The more the impact force is reduced.

Question 4

E. Acceleration?

Answer 4

A = change in Velocity / time taken

Question 5

E. Force?

Answer 5

F = mass * change in Velocity / time taken

Question 6

E. Impact force?

Answer 6

Impact force = change of momentum / impact time

Question 7

How do cycle helmets and cushioned surfaces reduce impact forces?

Answer 7

By increasing impact time.

Question 8

How do air bags and seat belts help?

Answer 8

By spreading the force over a bigger area and increasing impact time.

Question 9

How can you find the speed of a car before an impact?

Answer 9

Conservation of momentum.

Question 10

E. Hooke’s law?

Answer 10

Force applied = spring constant * extension

F=k*e

Question 11

Extension of the spring is directly proportional to…

Answer 11

The force applied ( as long as the limit of proportionality isn’t exceeded.)

Question 12

E. Extension?

Answer 12

Extension = length at stage - original length

Question 13

When is an object elastic?

Answer 13

If it returns to its original shape after removing the force deforming it.