Answers to AQA GCSE Balancing Moments made more complex

Calculations using Principle of Moments

Force 1, F₁ x distance 1, d₁= Force 2, F₂ x distance 2, d₂

Practice questions

1.Use the image below to answer the following questions

The weight of the box on the trolley is 500N. The line of action for the weight force is 0.25m from the pivot. A pull force is applied to the handle that is 1.3m from the pivot.

Calculate the size of the pull force F₁.

Force 1, F₁ x distance 1, d₁= Force 2, F₂ x distance 2, d₂

d₁ = 1.3m, F₂ = 500N, d₂ = 0.25m

F₁ = (F₂ x d₂)/d₁

F₁ = (500N x 0.25m)/1.3

F₁ = 96.1N

To help you understand better the anticlockwise and clockwise moments have been drawn onto the diagram below:

2.Use the image below to help you to answer the following question.

Calculate the size of the counter balance force.

Force 1, F₁ x distance 1, d₁= Force 2, F₂ x distance 2, d₂

F₁ = 3000N, d₁ = 1m, F₂ = ?N and d₂ = 1.5m

F_{2 =} (F₁ x d₁₎ x d₂

F₂ = (3000N x 1m)/1.5m

F₂ = 2000N

To help you understand better the anticlockwise and clockwise moments have been drawn onto the diagram below:

3. Use the image below to answer the following question.

Man doing a wheelie on a bike to show moments

The position of the pivot is on the back wheel. There is a distance of 0.2m from pivot to the line of action for the force of 500N. There is a distance of 1.3m from the pivot to the line of action for F₂. Calculate the size of F₂. Force 1, F₁ x distance 1, d₁= Force 2, F₂ x distance 2, d₂ F₁ = 500N, d₁ = 0.2m, F₂ = ?N and d₂ = 1.3m F_{2 =} (F₁ x d₁₎ x d₂ F₂ = (500N x 0.2m)/1.3m F₂ = 76.9 To help you understand better the anticlockwise and clockwise moments have been drawn onto the diagram below: