- #1

bewger

- 6

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## Homework Statement

When the block is pulled out to x = +5.0 cm, we must apply a force of magnitude 460 N to hold it there. We pull the block to x = +12.0 cm and then release it.

The 3 figures can be described by this.

(a) A spring in its relaxed state. The origin of an x-axis has been placed at the end of the spring that is attached to a block.

(b) The block is displaced by dvec, and the spring is stretched by a positive amount x. Note the restoring force Fvecs exerted by the spring.

(c) The spring is compressed by a negative amount x. Again, note the restoring force.

For each of the following, find how much work the spring does on the block when the block moves from the first point given to the second point given

(a) xi = 6.0 cm to x = 4.5 cm

(b) xi = 6.0 cm to x = -4.5 cm

(c) xi = 6.0 cm to x = -6.0 cm

(d) xi = 6.0 cm to x = -12.0 cm

## Homework Equations

F_s = -kd

F_x = -kx

W_s = .5*k*x_i^2 - 0.5*k*x_f^2

## The Attempt at a Solution

How do i get k from what's given?

Is it something like F_x/x = k?

So 460/.05 = 920?