19) Springs and Materials

Question 1

State Hooke’s law.

Answer 1

The force needed to stretch a spring is directly is proportional to the extension up to the limit of proportionality.

Question 2

Explain what is meant by the limit of proportionality.

Answer 2

Point beyond which force is no longer proportional to extension.

Question 3

Define tensile strain.

Answer 3

extension divided by its original length.

Question 4

Discuss whether the energy stored in the series spring arrangement is less, or greater, or the same as in the parallel arrangement.

Answer 4

-series has a greater store.
-extension is more in series and the force is the
same in both situations.
-energy stored is proportional to extension.

Question 5

Give a reason why a graph shows a rubber cord does not obey Hooke’s law.

Answer 5

the lines are not straight.

Question 6

Explain the meaning of the term plastic deformation.

Answer 6

permanent deformation.

Question 7

Explain what is meant by a thermal neutron.

Answer 7

• Slow moving neutrons

- they are in thermal equilibrium with the moderator