A truck pulls boxes up an incline plane. The truck can exert a maximum force of 5,700 N5,700N. If the plane's incline is (2 pi )/3 2π3 and the coefficient of friction is 8/5 85, what is the maximum mass that can be pulled up at one time?

1 Answer
Nov 8, 2017

"8130.2 kg"8130.2 kg

Explanation:

If mm is the mass of the boxes and MM is the mass of the truck:

N =N= the normal force

So, we want to know the maximum mass of the boxes.

mgsin(theta) + Mgsin(theta) + F_f = 5700mgsin(θ)+Mgsin(θ)+Ff=5700

This is because when the boxes reach the maximum mass, the truck at this stage cannot pull more boxes. Thus, the force that pulls everything up the incline must be equal to the forces against the motion.

mg sin(theta) ->mgsin(θ) The component of the weight of the boxes along the plane.

Mg sin(theta) ->Mgsin(θ) The component of truck's weight along the plane.

Now, F_fFf or static friction is

F_f = "the coefficient of friction" xx "the normal force"Ff=the coefficient of friction×the normal force

Here

N = Mg cos(theta)N=Mgcos(θ)

The problem is that MM is not given. I will make another equation;

5700 - Mgsin(theta) - mu xx Mgcos(theta) = 05700Mgsin(θ)μ×Mgcos(θ)=0

Here

mu =μ= the coefficient of friction

Rearrange the equation to get MM

M = 5700/(gsin(theta) + mu xx gcos(theta))M=5700gsin(θ)+μ×gcos(θ)

Now plug in the numbers to get

M= "8800.2 kg"M=8800.2 kg

Now use that equation

mgsin(theta) + Mgsin(theta) + F_f = 5700mgsin(θ)+Mgsin(θ)+Ff=5700

Solve for mm:

m = (5700-F_f)/(gsin(theta) ) - Mm=5700Ffgsin(θ)M

After you plug in the numbers you will get :

m = "8130.2 kg"m=8130.2 kg