How to calculate the change in kinetic energy on a plane?

AI Thread Summary
To calculate the change in kinetic energy of a crate being pulled up a rough incline, the applied force, friction, and gravitational components must be considered. The initial parameters include a mass of 11 kg, an incline angle of 20°, and an initial velocity of 1.55 m/s. The net force acting on the crate is derived from the applied force minus friction and the parallel component of gravity. The user initially calculated the work done incorrectly by not accounting for the gravitational force acting down the incline. Correcting this leads to a more accurate calculation of the change in kinetic energy, which is essential for solving the problem.
governergrimm
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Homework Statement


A crate is pulled by a force (parallel to the incline) up a rough incline. The crate has an initial speed shown in the figure below. The crate is pulled a distance of 9.33 m on the incline by a 150 N force. The acceleration of gravity is 9.8 m/s 2 . What is the change in kinetic energy of the crate? Answer in units of J.
Mass = 11kg
Angle of the incline (θ)= 20°
Initial Velocity = 1.55 m/s
μ = .308
D= 9.33 Meters
Force Applied = 150N
g=9.8

Homework Equations


Ff= μN
W=Fd=ΔKE
Fapplied -Ff=Fnetx
FnetVertical =0

The Attempt at a Solution


N-mgcosθ=0
N=mgcosθ
Fa-Ff=Fnet
Fa-μN
Fa-μmgcosθ=Fnet
150-(.308)(11)(9.8)cos(20°)=118.8
W=ΔKE = 118.8(9.33) = 1399.5

Not sure what I am missing but it is incorrect.
 
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You've forgotten the other (parallel-to-the-plane) component of gravity.
 
My force should look like this then?

force applied - force friction - mgsinθ= Fnet

Is that all that I'm missing?
Thanks!
 

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