5.3 Forces and elasticity

Question 1

Explain the relationship between the force applied and the extension of an elastic object

Answer 1

The extension is directly proportional to the force applied, provided that the limit of proportionality is not exceeded.

Question 2

What is meant by an inelastic (plastic) deformation?

Answer 2

A deformation which results in the object being permanently stretched. The object doesn’t return to its original shape after the force is removed.

Question 3

State the equation relating force, spring constant and extension. Give appropriate units.

Answer 3

Force = spring constant x extension

Force (N), Spring constant (N/m), Extension (m)

Question 4

What type of energy is stored in a spring when it is stretched?

Answer 4

Elastic potential energy

Question 5

What can extension be replaced with in the equation for spring force?

Answer 5

Compression