Calculating Forces

Question 1

How would you use a scale drawing to find resultant forces?

Answer 1

1) Draw all the forces acting on an object, to scale, ‘tip-to-tail’.
2) Then draw a straight line from the start of the first force to the end of the last force — this is the resultant force.
3) Measure the length of the resultant force on the diagram to find the magnitude and the angle to find the direction of the force.

Watch this video link if unsure: https://youtu.be/U8z8WFhOQ_Y?si=LRRSeQ8toKlBGeIV

Question 2

A man is on an electric bicycle that has a driving force of 4N north. However the wind produces a force of 3N east. Find the magnitude and direction of the resultant force

Answer 2

1)Start by drawing a scale drawing of the forces acting.
2) Make sure you choose a sensible scale (e.g. 1 cm = 1 N)
3)Draw the resultant from the tail of the first arrow to the tip of the last arrow.
4)Measure the length of the resultant with a ruler and use the scale to find the force in N.
5) Use a protractor to measure
the direction as a bearing.

Question 3

What does it mean when all forces acting on an object result in a resultant force of zero?

Answer 3

When all forces acting on an object combine to give a resultant force of zero, the object is in equilibrium.

Question 4

How can you find a missing force on an object in equilibrium?

Answer 4

1)draw out the known forces to scale and tip-to-tail.
2)connect the end of the last force to the start of the first force.
3)This line represents the missing force, which can be measured for its size and direction

Watch this video link if unsure: https://youtu.be/U8z8WFhOQ_Y?si=LRRSeQ8toKlBGeIV

Question 5

How can forces acting at awkward angles be made easier to deal with?

Answer 5

by splitting them into two components at right angles to each other, usually horizontal and vertical.

Question 6

What does it mean to resolve a force?

Answer 6

Resolving a force means splitting it into its horizontal and vertical components

Question 7

How do you resolve a force?

Answer 7

This is done by drawing the force to scale on a grid and then adding the horizontal and vertical components along the grid lines, making them easier to measure.