Forces

Question 1

What is the unit for force and it’s symbol?

Answer 1

Newtons, N

Question 2

How do you calculate net force for a watermelon with forces of left 2N and right 1N

Answer 2

Fnet = 2 - 1 = 1N left

Question 3

Calculate the net force on a carrot, 0.2N up and 1.6N down

Answer 3

1.6 - 0.2 = 1.4N Downwards

Question 4

Calculate the net force on a tomato, 1N left, 6N right, 1.2N upward and 1.2N downward.

Answer 4

Fnet = 6 - 1 = 5N right, the upwards and downwards forces are balanced

Question 5

What is Fg or weight force?

Answer 5

A force due to gravity acting downwards on the object

Question 6

What is Fs or support force?

Answer 6

When the weight force of an object is applied to another object, that object applies an equal force in the opposite direction. E.g. when you put your laptop on a table the table applies an equal force in the opposite direction

Question 7

What is Ft or thrust force?

Answer 7

A force which pushes an object in the forwards direction

Question 8

What is Ff or Friction force?

Answer 8

A force which opposes the thrust force, it acts in the reverse direction

Question 9

What is the difference between mass and weight?
What are the units for both?

Answer 9

The mass of an object is how much matter it has.
The weight of an object is how much force is used to pull the mass towards the ground.

Mass = kg
Weight = N

Question 10

What is the formula to work out weight?

Answer 10

Fw = mg

Question 11

What is the formula for working out Fnet, net force?

Answer 11

Fnet = ma

Question 12

What is the formula for working out acceleration, given mass and force?

Answer 12

Fnet = ma so a = Fnet / m

Question 13

If an object is moving at a constant speed, what does this mean about the forces acting on it?

Answer 13

The forces must be balanced as the object is moving at a constant speed so the net force is 0N, this is Newton’s first law of motion.
Also since Fnet = ma, a = Fnet / m. If the acceleration is 0, then the net force must be 0