Use Hooke's Law to determine the work done by the variable force in the spring problem. A force of 350 newtons stretches a spring 30 centimeters. How much work is done in stretching the spring from 50 centimeters to 80 centimeters

Explanation:

350 N force stretches the spring by 30 cm

spring constant K = 350 / 0.30 = (350 / 0.3) N / m

To calculate work done by a spring force we proceed as follows

spring force when the spring is stretched by x = Kx

This force is variable so work done by it can be calculated by integration

Work done by it in stretching from x₁ to x₂

W = ∫ F dx

= ∫ Kx dx with limit from x₁ to x ₂

= 1/2 K ( x₂² - x₁² )

Putting the given values of x₁ = 0.50 m , x₂ = 0.8 m

Work done

= 1/2 x (350 / 0.3)x ( 0.80² - 0.50² )

= 227.50 J

the part of the wave he is travelling on is the crest