Question

The left end of a spring is attached to a wall. When Bob pulls on the right end with a 200 N force, he stretches the spring by 20 cm. The same spring is then used for a tug-of-war between Bob and Carlos. Each pulls on his end of the spring with a 200 N force. How far does the spring stretch

Answer 1

Answer:

40 cm

Explanation:

Since Bob pulls with a force of F = 200 N when the spring is attached to the wall and it extends a length x = 20 cm, from Hooke's law,

F = kx where k = spring constant

So, k = F/x = 200 N/20 cm = 10 N/cm

Now, sine both Bob and Carlos pull with a force of F = 200 N in opposite directions, the spring stretches about its center and has an extension, x' in each direction.

So, from F = kx

x = F/k = 200 N/10 N/cm = 20 cm

So, the spring stretches 20 cm in both directions.

So, the total extension is thus x' + x' = 2x' = 2(20 cm) = 40 cm