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meganw
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Homework Statement
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
Homework Equations
Ff= Mk(Normal Force)
F=m(acceleration)
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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