Aspring with spring constant of 21 n/m is stretched 0.16 m from its equilibrium position. how much work must be done to stretch it an additional 0.15 m

Explanation:

We use the equation to calculate the work from a point to a point on a spring:

where is the work, and is the spring constant, .

For this problem since the spring was first stretched 0.16m, , and then was stretched an aditional 0.15m, so .

Now we substitute the known values in the equation to find the work:

The work that must be done to stretch the spring an aditional 0.15m is 0.74 Joules

0.19 m/s and 0.45 m/s