What is the spring constant (in n/m) of a spring that stores 100 J of elastic potential energy when it is stretched 5 m?

8N/m

Explanation:

The elastic potential energy stored can be calculated using the equation:

elastic potential energy = 0.5 * spring constant * (extension) 2

assuming it is not stretched beyond the limit of proportionality.

Then calculate using the values in the question:

100J = 0.5 * spring constant * 5²

200J = spring constant * 25

spring constant = 200J : 25m²

spring constant = 8J/m²

spring constant = 8N/m