Motion along a line.

1. Oct 4, 2009

jiwon

1. The problem statement, all variables and given/known data

A boy pushes a 5-kg machine along a horizontal floor with a force, P, which makes an angle, theta=30 degree below the horizontal. The coefficients of static and kinetic friction between the machine and the floor are 0.5 and 0.3 respectively. The machine is initially at rest.

a.) find the maximum force of static friction that must be overcome by the applied before the machine moves.
b.) what is the value of the force P needed to move the machine at a constant acceleration of 1.5 m/s^2 along the floor?
c.) suppose he pushes the machine with just enough force to move the machine, and continues to push with the same force after the machine starts moving, calculate the acceleration of the machine while in motion.

2. Relevant equations
dion't know what i used.

3. The attempt at a solution

just want to know if these answers were right.
2.)a. t= 39.77N
b.) 31.005 N
c.) a=2.76 m/s^2

I don't know if these are right! Please help me to determine whether it's right or not!! and show me how you do the steps.

I'm just not sure on where to start on it. Any help on it is appreciated!

Last edited: Oct 4, 2009
2. Oct 7, 2009

jiwon

How do I delete this?

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