# Physics ramp/acceleration problem!

by scorks
Tags: acceleration, angled ramp, gravity, mass
 P: 5 Block A has a mass of 5.26 kg and is on a rough incline of 16.0°to the horizontal. Block B has a mass of 4.80 kg and the coefficient of kinetic friction between Block A and the plane is 0.204. What is the acceleration of the blocks? Equations= fnet=ma Attempt:(4.8+5.26)a=(4.8)g-(5.26)gsin(16°)-(μ)(9.8)(5.26)(cos(16°)) Therefore a=3.00m/s^2 This comes out to be the wrong answer, according to the key. Help?!
 P: 7 I get 1.7 m/s^2. Tell me if thats right and i will explain. i think you went wrong on the friction bit. Friction = UN and force N=FG. You didn't add all your masses for some reason on the friction part.
P: 5
 Quote by Eango I get 1.7 m/s^2. Tell me if thats right and i will explain. i think you went wrong on the friction bit. Friction = UN and force N=FG. You didn't add all your masses for some reason on the friction part.
Nope, unfortunately they say that's wrong D:

P: 7

## Physics ramp/acceleration problem!

I see what i did XD
Lets see.... (If this isn't right, ill shoot myself...JK)

Sum of F = ma
Fg - Ff = ma
mg - UN = ma
m1+m2gsin(16) - U X m1+m2cos(16)=m1+m2(a)
a= m1+m2gsin(16) - Ux m1+m2cos(16)/ m1+m2
a= 5.26+4.8sin(16) - 0.204 X 5.26+2.8cos(16)/ 5.26+2.8
a=-1.84
 P: 7 a = -1.84 m/s^2 :P

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