# Physics lab on energy need help

Physics lab on energy need help!!

## Homework Statement

Need to find velocity and time when I know all lengths/heights. Need to look at picture to fully understand my problem.

## Homework Equations

Projectile motion equations... And velocity equations..

## The Attempt at a Solution

On picture

#### Attachments

• image.jpg
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Pythagorean
Gold Member
Since you know the height of the ramp, you know the potential energy which all gets converted into kinetic energy coming off the ramp. Since you know the kinetic energy, you know the velocity... since you know the velocity, and the height of the table, you know how far it will go before it hits the ground.

Ok so my kinetic energy would be mass x 9.8 x .05 (height of ramp). Is this right? I don't know the mass though.

jtbell
Mentor
I don't know the mass though.

Maybe you'll get lucky and it will cancel or drop out of your solution. Okay so I came up with v^2= 2gh. 2 x 9.8 x .05 = .98 and the square root of .98 is .99. This is my velocity. Then to find my time do I divide my velocity by .75?

Pythagorean
Gold Member
no, the velocity is is in the x direction right? How fast will it accelerate towards the ground in the y direction?