Moments and Momentum

Question 1

What happens when a force is a applied to loosening a bolt?

Answer 1

The force applied creates a moment about the pivot

Question 2

Equation for moments

Answer 2

Moment= force x (perpendicular) distance between force and pivot

Question 3

What is the unit for moments?

Answer 3

Nm

Question 4

What happens if the force and distance aren’t perpendicular?

Answer 4

Use a dashed line to work out the perpendicular distance

Question 5

What does the resultant moment tell you?

Answer 5

The direction of rotation

Question 6

In equilibrium position

Answer 6

Total clockwise moments=total anti-clockwise moments

Question 7

What is the centre of mass?

Answer 7

The point at which all the mass appears to act

Question 8

Momentum equation

Answer 8

Momentum = mass x velocity

Question 9

What is momentum measured in?

Answer 9

Kgm/s

Question 10

What quantity is momentum?

Answer 10

Vector

Question 11

What does the law of conservation of momentum state?

Answer 11

“In any collision or explosion, the total momentum before equals the total momentum after, provides no external force acts”

Question 12

What must happen in an explosion?

Answer 12

The momentum of each object must be equal and opposite

Question 13

Equation for kinetic energy

Answer 13

KE = 1/2mv^2

Question 14

What is a collision called where the kinetic energy is lost?

Answer 14

Inelastic collision

Question 15

Equation for force

Answer 15

Force = final momentum - initial momentum / time

Time - change in momentum

Question 16

How to answer increasing time to reduce force question?

Answer 16

1) object comes to rest
2) momentum falls to zero
3) time for this is large
4) reduction in force

Question 17

Newton’s 1

Answer 17

Objects remain in their state of motions unless acted on by a force

Question 18

Newton’s 2

Answer 18

The greater the force acting on an object, the more it accelerates

Question 19

Newton’s 3

Answer 19

If a force acts on object A by object B, then an equal and opposite force acts on object B from object A

Question 20

When is an object stable

Answer 20

If when given a toppling force, will return to land on its base (if the line of action of the weight lies within the base)

Question 21

What makes an object more stable

Answer 21

Wider base

Lower centre of mass