Calculating Velocity of Sphere on Inclined Plane

[moondawg]

Homework Statement

A large sphere rolls wothout slipping across a horizontal surface. The sphere has a constant translational speed of 10m/s,mass of 25 kg, radius of .2m. The moment of inertia of the sphere about its center of mass is I=2mr²/5. The sphere approaches a 25 degree incline of height 3m as shown above and rolls up the incline without slipping. Calculate the spheres velocity just as it leaves the top of the incline.

Homework Equations

The Attempt at a Solution

I found total kinetic energy by adding translational kin enery, rotational kin energy and (mgh)... i got 3015J and then set that number equal to the equation for kin energy (1/2mv²) and found my new v and got 15.53 m/s but that can't be correct bc if its initial vel as it was going toward the ramp was 10 m/s then why would it speed up if its going up a ramp? idk what i did wrong pleaseee help.!

 

[Doc Al]

I found total kinetic energy by adding translational kin enery, rotational kin energy and (mgh)...

Why did you add mgh? Explain exactly what you did.