# May the Force be 81.2 N

1. Jan 29, 2014

### Medgirl314

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

A 15 kg crate rests on the floor. The coefficient of friction between the crate and the floor is 0.28. How much horizontal force is needed to accelerate the crate at 3.0 m/s^2?

2. Relevant equations

Fnet=ma

3. The attempt at a solution
m=15 kg
F-f=ma
F-$M$N=ma
F-$M$mg=ma
F=ma+$M$mg
F=15*3+.38*15*9.8
F=81.16 N.
For a final rounded answer of: F=81.2 N.

Thanks!

2. Jan 29, 2014

### SteamKing

Staff Emeritus
I don't get your result, even with μ = 0.28. Try your calculator again.

3. Jan 29, 2014

### Medgirl314

Oops, I thought I corrected that, sorry! Weird, I somehow mixed up the digits. Does 86.16, rounded to 86.2, sound better?

Thanks!