- #1

Patdon10

- 85

- 0

## Homework Statement

A spring with a spring constant of 500 N/m is used to propel a 0.42-kg mass up an inclined plane. The spring is compressed 30 cm from its equilibrium position and launches the mass from rest across a horizontal surface and onto the plane. The plane has a length l = 3 m and is inclined at 32°. Both the plane and the horizontal surface have a coefficient of kinetic friction with the mass of 0.35. When the spring is compressed, the mass is at distance d = 1.6 m from the bottom of the plane.

(a) What is the speed of the mass as it reaches the bottom of the plane?

1Your answer is incorrect.

(b) What is the speed of the mass as it reaches the top of the plane?

2

(c) What is the total work done by friction from the beginning to the end of the mass's motion?

## Homework Equations

E = K + PE

K

_{i}+ PE

_{i }= K

_{f}PE

_{f}

Elastic Potential Energy = (1/2)kx

^{2}

## The Attempt at a Solution

I'm pretty sure I can solve this fairly easily after I figure out part A. However, Part A is giving me a lot of trouble.

K_i + Elastic PE_i = K_f + Elastic PE_f

0 + (1/2)(500)(1.6

^{2}) = (1/2)(0.42)(v

^{2}) + 0

v = 55.205 m/s

That's wrong, any advice?

Thanks in advance.