Newton

Question 1

Newtons 1st law

Answer 1

A body will remain at rest or continue to move in a straight line at a constant velocity unless an external force acts on it

Question 2

Newtons 2nd law

Answer 2

The resultant force on an object is directly proportional to the rate of change of momentum of the object and the momentum change takes place in the same direction as the force

Question 3

Newtons 3rd law

Answer 3

If object A exerts a force on object B, then object B will exert an equal and opposite force on object A

Question 4

Equation for momentum

Answer 4

p=mv

Question 5

Rate of change of momentum

Answer 5

Net force

Question 6

Conservation of momentum

Answer 6

Assuming that no external forces act, total momentum is always conserved

Question 7

Two equation for impulse

Answer 7

I=Ft

I=mv-mu

Question 8

How is impulse related to momentum

Answer 8

It equals change in momentum

Question 9

Area under a force time graph

Answer 9

Impulse

Question 10

Rules for elastic collision

Answer 10

Momentum conserved

Kinetic energy conserved

Question 11

Rules for inelastic collision

Answer 11

Momentum conserved

Kinetic energy not conserved

Question 12

When can F=ma not be used

Answer 12

When objects are travelling close to the speed of light (resulting in their mass changing)

Question 13

The essence of all car crash safety features

Answer 13

Increasing the time that it takes for the car and passengers to change their speed. This results in a lower force for the same impulse

Question 14

Crumple Zone and its effects (2)

Answer 14

Areas at the front of the car that crumple upon impact

• Absorb some kinetic energy by deforming
• Increase the time it takes for the car to slow down which reduces the forces on the passengers