# A crate is pulled by a force (parallel to the incline) up a rough incline. The crate

1. Oct 19, 2011

### BallerRegis

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 9.17 m on the
incline by a 150 N force.
The acceleration of gravity is 9.8 m/s2 .
a) What is the change in kinetic energy of
the crate?

b) What is the speed of the crate after it is
pulled the 9.17 m?

For part A i tried
F-mg[sin theta - (friction x cos theta)] and got 135.232 but got wrong answer then i tried multiplying it by the distance and got it wrong.
Also i tried using F - [ μ m g cos θ ] and got it wrong

2. Oct 19, 2011

### Delphi51

Re: A crate is pulled by a force (parallel to the incline) up a rough incline. The cr

The question appears to be incomplete. Do you know the angle, initial speed and coefficient of friction? If so, your calculation of
"F-mg[sin theta - (friction x cos theta)]"
looks like a good start. Here F = 150, friction = μmg. The result of the calc is the total force on the mass, which you can use in F = ma to find the acceleration. Once you have that, you can use accelerated motion formulas to find the Vf and then the Ek to complete part (a).

3. Oct 19, 2011

### BallerRegis

Re: A crate is pulled by a force (parallel to the incline) up a rough incline. The cr

ok i got part a which was

533.0427

how do i get part B
i tried

V= square root 2(553.0427)/11