4.5.3 Forces and Elasticity

Question 1

What does it look like on a graph when something follows Hooke’s Law?

Answer 1

A straight, diagonal line going from the origin (0,0).

Question 2

What do we call the pattern that Hookean objects show on a graph?

Answer 2

Directly proportional.

Question 3

What does being directly proportional actually mean in terms of spring force and extension?

Answer 3

As you increase the force by a set amount (e.g. 1N), the extension will also increase by a set amount (e.g. 20mm).

Question 4

600g is hung on a spring in a science lab. The spring stretches 48cm. What is its spring constant? What does that actually mean?

Answer 4

600g = 6N, 48cm = 0.48m
6/0.48 = 12.5
12.5N/m - This means that 12.5N is required to stretch it to 1m.

Question 5

A spring stretches 0.6m and has a spring constant of 20N/m. How much work is done to make it stretch?

Answer 5

0.5 x 20 x 0.6^2 = 3.6J (Elastic potential energy = work done to stretch a spring).