Young Modulus, hooke’s law and stress strain

Question 1

What does Hooke’s law say about extension and force?

Answer 1

Extension is proportional to the force applied

Question 2

What happens when a metal wire is supported at the top and then a weight is attached to the bottom

Answer 2

The metal wire will start to stretch

Question 3

What is Hooke’s law equation?

Answer 3

Force = spring constant x extension
F=kx
K is a constant that depends on the object being stretched
K is called the force constant and has units Nm-1.

Question 4

To a spring, what happens when you apply a pair of opposite forces?

Answer 4

The metal spring will change length.

Question 5

How does Hooke’s law work for compressive and tensile forces?

Answer 5

For a spring, the spring constant works just as well for compressive and tensile forces. This does not apply to all materials.

Question 6

What materials obey Hooke’s law?

Answer 6

It applies to most materials until it obeys up to a point.

Question 7

When does Hooke’s law stop working.

Answer 7

It stops working when the load is great enough.

Question 8

Describe Hooke’s law graph of a typical metal wire or spring?

Answer 8

• The first part of the graph shows Hooke’s law being obeyed as there is a linear relationship between force and extension.
• When the force becomes great enough, the graph starts to curve. This is because it reaches its limit of proportionality.
• Once it has gone past it, it has reached its elastic limit. If you exceed the elastic limit, the material will be permanently stretched. When all force is removed, the material will be longer than at the start.

Question 8

Describe Hooke’s law graph of a typical metal wire or spring?

Answer 8

Describe Hooke’s law graph of a typical metal wire or spring?

Question 9

Describe Hooke’s law graph of a typical metal wire or spring?

Answer 9

• The first part of the graph shows Hooke’s law being obeyed as there is a linear relationship between force and extension.
• When the force becomes great enough, the graph starts to curve. This is because it reaches its limit of proportionality.
• Once it has gone past it, it has reached its elastic limit. If you exceed the elastic limit, the material will be permanently stretched. When all force is removed, the material will be longer than at the start.

Question 10

What does a spring look like in series?

Answer 10

The springs are connected