yr 9 recap

Question 1

tell me these things about force:
- what’s it measured in?
- what does it include?
- what is force?

Answer 1

• Force is measured in Newtons (N),
• has both a magnitude and a direction.
• Therefore, force is a vector quantity.

Question 2

non-contact
examples of a non-contact force?

Answer 2

A non-contact force can be exerted without objects physically touching

• Electrostatic force
• Gravitational force
• Magnetic force

Question 3

contact force
examples of a contact force?

Answer 3

A contact force can only be exerted when objects are physically touching

• Tension force
• Friction force
• Normal contact force
• Air resistance

Question 4

why do we need Normal contact force?
and what’s another name for it?

Answer 4

‘Reaction force’
to keep the object in position and to keep it from falling of the table

Question 5

Is air resistance a contact or non-contact force? Explain why.

Answer 5

Air resistance is a contact force. This is because it is due to the physical contact (collisions) between an object and the particles in the air.

Question 6

force definition

Answer 6

A push or pull, that acts on an object due to it’s interaction with another object

e.g. a hand pushing a box

• is a vector quantity
  meaning it contains both magnitude and direction.

Question 7

The formula that links force and extension is…

Answer 7

F = ke

Question 8

What happens to the energy in a spring when it is stretched and then released?

Answer 8

When a spring is stretched, energy is transferred to its elastic potential energy store.

Then when the spring is released, most of that energy is transferred to kinetic energy

Question 9

The formula for elastic potential energy is:

Answer 9

Ee = ​1/2 x ​k x (e(squared)

Question 10

formula for speed?

Answer 10

distance/ time

Question 11

acceleration formula

Answer 11

change in velocity / time taken