[Springs]

Question 1

1. Tensile

Answer 1

Tensile force is an equal and opposite force acting on a material to stretch it. A tensile deformation is the change in shape of an object due to tensile forces.

Question 2

2. Compressive

Answer 2

Compressive force is two or more forces together that reduce the length or volume of an object. A compressive deformation is the change in shape of an object due to compressive forces.

Question 3

3. Deformation

Answer 3

Any change in the shape or size of an object due to an applied force (through work) or a change in temperature (through heat). The first case can be a result of tensile (pulling) forces, compressive (pushing) forces, shear, bending or torsion (twisting).

Question 4

4. Extension

Answer 4

x. The increase in length of an object when a tensile force is exerted on it.

Question 5

5. Compression

Answer 5

x. The decrease in length of an object when a compressive force is exerted on it.

Question 6

6. Hooke’s Law

Answer 6

F α x. The extension of a spring is directly proportional to the force applied; this is as long as the elastic limit is not exceeded. A force–extension graph is a straight line through the origin. F α x -> F = k x.

Question 7

7. Elastic Limit

Answer 7

The value of stress or force beyond which elastic deformation becomes plastic deformation and the material will no longer return to its original size and shape when the force is removed.

Question 8

8. Force (or Spring) Constant

Answer 8

k. Force per unit extension. ‘Stiffness’ of the spring. The gradient of a force–extension graph. Measured in Newtons per metre, Nm-1. k = F / x.