Balanced Moments and Levers

Question 1

If something is balanced, describe the moments

Answer 1

The anticlockwise moments are equal to the clockwise moments, the object won’t turn

Question 2

Example: Your younger brother weighs 300 N and sites 2 m from the pivot of a seesaw. If you weigh 700 N where should you sit to balance the seesaw?

Answer 2

For the seesaw to balance: Total anticlockwise moments = Total clockwise moments

anticlockwise moments = clockwise moments 
300 * 2  = 700 * y
y = 0.86 m 
//Ignore the weight of the seesaw - its centre of mass is on the pivot, so it doesn't have a turning effect

Question 3

Leavers use the idea of [ ] to make it easier for us to do work

Answer 3

balanced moments

Question 4

The moment need to do work =

Answer 4

force * distance from the pivot.

So the amount of force needed to do work depends on the distance the force is applied from the pivot

Question 5

How to levers make there need less force needed to get the same moment?

Answer 5

Levers increase the distance from the pivot at which the force is applied

Question 6

Why are levers known as force multipliers?

Answer 6

They reduce the amount of force that’s needed to get the same moment by increasing the distance

Question 7

Give 2 examples of levers to reduce the work that needs to be done

Answer 7

Wheelbarrows and Scissors