# Homework Help: Man moving crate

1. Jan 15, 2008

### Discalculiate

My teacher gave us practice questions for the midterm. Can't for the life of me remember how to do this. Any hints would be greatly appreciated. I'm not just trying to bum answers off you guys; I really don't know where to start.

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

Чs = .2 (the Ч is backwards - can't find a closer symbol, but you know what I mean)
Чk = .1
A man is pulling a 100 kg crate to the right. Fman = 150 N
a) What is the force? [er, not entirely sure what he means by this?]
b) Fman to get the crate moving?
c) Fman to move crate at constant speed?

2. Relevant equations

Unknown

3. The attempt at a solution

heh.

2. Jan 15, 2008

### Staff: Mentor

You must show some work to get help here. What is the general equation relating the horizontal force on an object like that crate, the weight of the crate, and the coefficients of static and dynamic friction $$\mu_s$$ , $$\mu_d$$ ?

3. Jan 15, 2008

### Discalculiate

Well I know fsmax = Чs(N)(9.8)

So fmax = (.2)(150)(9.8)? which would be 294 N

Is that what he wants for part a?