- #1

Jpyhsics

- 84

- 2

## Homework Statement

As part of an elaborate prank, a well-greased watermelon (m=4.72 kg) is placed on a ramp inclined with angle

*θ*=27.4° with respect to the horizontal. Because of the grease, the coefficients of static and kinetic friction are

*µ*s= 0.560 and

*µ*k= 0.392 respectively. The watermelon is attached to the wall, parallel to the ramp, by a spring with constant

*k*=175.2 N/m. What is the farthest distance down the ramp that the watermelon can be pulled away from the spring equilibrium and placed at rest on the surface without the spring pulling the watermelon back up the ramp? Express your answer in metres

## Homework Equations

F=ma

## The Attempt at a Solution

ΣF

_{x}=mgSinθ-kx-μ

_{s}mgCosθ

Rearranged to make:

x=(mg(μ

_{s}Cosθ-Sinθ))/(-k)

x=-0.00977m

I used the coefficient of static friction, because it was at rest. Does my solution look correct?

I have included an image of my solution as well.