Force and extension of a spring

According to Hooke's law; Force is equal to -

• Spring Constant × Extension

• Spring Constant ÷ Extension

• Spring Constant + Extension

_________ is the unit of Spring Constant

• N

• N/m

• m

A force of 400 N is applied to stretch a spring which has a spring constant, k=100 N/m. How much does the spring stretch past its free length?

• 0.4 m

• 2.34 m

• 4 m

• 5.17 m

Which of the following springs is the stiffest?

• A spring that requires a force of 2000 N to compress it by 5 m.

• A spring that requires a force of 4000 N to stretch it by 10.0 m.

• A spring that requires a force of 2400 N to compress it by 4m.

• A spring that requires a force of 4800 N to stretch it by 12 m.

The graph shows the relationship between force and extension as a spring is extended. What is the name of point A?

• Point A is the optimum force.

• Point A is the limit of extension.

• Point A is the limit of force.

• Point A is the limit of proportionality

If a spring is extended beyonds it elastic limit, what two things does this mean for the spring?

• The spring will no longer return to its original length.

• The spring will no longer obey Hookes Law.

• The spring will no longer extend.

• The spring will bounce back to its original length.

In a school experiment, a force of 2N auses a spring to stretch from 20mm to 36mm. Calculate the spring constant.

• 0.125N/m

• 8N/mm

• 40N/m

• 125N/m

To convert mm to m you need to...

• divide by 1000

• multiply by 1000

• divide by 100

• multiply by 100

The extension is...

• the length of the spring

• the difference between the new length and original length of the spring

• the original length of the spring

What is the independant variable in this experiment?

(a)