(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two crates, of mass 80 kg and 210 kg, are in contact and at rest on a horizontal surface (Fig. 5-26). A 750 N force is exerted on the 80 kg crate. The coefficient of kinetic friction is 0.21.

(a) Calculate the acceleration of the system.

.53 m/s2 (to the right)[Note: This Answer is Correct]

(b) Calculate the force that each crate exerts on the other.

_________ N

(c) With the crates reversed, calculate the force that each crate exerts on the other .

_________ N

2. Relevant equations

Ff= Mk(Normal Force)

F=m(acceleration)

3. The attempt at a solution

I did A, and I got .53, but I can't get B. I guess I just don't understand how to do it.

I tried to calculate the force that Crate 1 exerts on Crate 2. I tried this but I got the wrong answer it says:

Fy(net)=m(a)=Fa-Ff

Ff=.21(Normal)

Normal=Fg=9.8(mass)=9.8(80)=784

Ff=.21(784)

Ff=164.64

Fy(net)=

80(.53)=Fa-164.64

Fa=207

It says that I'm wrong. :(

I also can't get C...I don't even understand how to begin that one though.

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# Homework Help: Newton's Forces Question

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