An ideal spring has a spring constant k = 20.0 N/m. What is the amount of work that must be done to stretch the spring 0.70 m from its relaxed length?

(1/2)k X^2

X is the amount of stretch

To find the amount of work done to stretch the spring, we can use the formula for work done by a spring:

W = (1/2) * k * x^2

Where:
W = Work done
k = Spring constant
x = Displacement from the relaxed length

In this case, the spring constant is given as k = 20.0 N/m, and the displacement from the relaxed length is x = 0.70 m.

Substituting these values into the formula, we get:

W = (1/2) * 20.0 N/m * (0.70 m)^2

Now, let's calculate the work done:

W = (1/2) * 20.0 N/m * (0.49 m^2)
= 4.9 N*m

Therefore, the amount of work that must be done to stretch the spring 0.70 m from its relaxed length is 4.9 N*m.