Forces and matter

Question 1

Explain using springs and other elastic objects that stretching, bending or compressing an object needs more than one force

Answer 1

• If a single force is applied the object will just move in the force’s direction
• If forced inwards from opposite sides = object will compress

Question 2

Difference between elastic and plastic deformation

Answer 2

Elastic: Object returns to original shape
Plastic: Object doesn’t return to it’s shape

Question 3

Describe the difference between linear and non-linear relationships between force and extension

Answer 3

Linear: Elastic, follows Hooke’s law, Elastic deformation
Non linear: Not elastic, doesn’t follow Hooke’s law, Plastic deformation

Question 4

What is hooke’s law

Answer 4

The extension of a spring is directly proportional to the force applied

Question 5

Explain why atmospheric pressure varies with height above
the Earth’s surface with reference to a simple model of the
Earth’s atmosphere

Answer 5

• The total weight of the air above a unit area at a certain altitude
• Atmospheric pressure decreases with increasing height above the earth’s surface