- #1

as2528

- 40

- 9

- Homework Statement
- A can of soup travels down an inclined plane which is 3.00 m long and makes an angle of 25 degrees with the horizontal. It travels this distance in 1.50 seconds. What is the final velocity, assuming the can of soup started at rest, a perfect roll is occurring, and friction is negligible?

- Relevant Equations
- (vf+vi)/2=vavg

vf^2=vi^2+2*a*s

a=gsin(theta)

a = 9.8*sin(25*pi/180)=>a=4.1417 m/s^2

vf^2=vi^2+2*a*s=>vf=sqrt(0^2+2*4.1417*3)=>vf=4.9850 m/s

Meanwhile the correct answer is:

(vf+vi)/2=>(vf+0)/2=2=>vf=4 m/s

Why is my answer wrong? It seems that the acceleration is what is wrong, but I don't understand why.

vf^2=vi^2+2*a*s=>vf=sqrt(0^2+2*4.1417*3)=>vf=4.9850 m/s

Meanwhile the correct answer is:

(vf+vi)/2=>(vf+0)/2=2=>vf=4 m/s

Why is my answer wrong? It seems that the acceleration is what is wrong, but I don't understand why.