# Answer Check for kinematic in 2-d

1. Sep 25, 2008

### Filenes

1. The problem statement, all variables and given/known data

In a local bar, a customer slides an empty beer mug down the counter for a refill. The bartender is momentarily distracted and does not see the mug, which slides off the counter and strikes the floor 1.10 m from the base of the counter. The height of the counter is 0.820 m.
(a) With what velocity did the mug leave the counter?
correct check mark m/s
(b) What was the direction of the mug's velocity just before it hit the floor?
wrong check mark

2. Relevant equations
I found (a) which is 2.68 m/s

3. The attempt at a solution

For b) i used sqrt(2.68^2+2.68^) = 3.79 and did,
theta = cos^-1(2.68/3.79) which is 45 degrees, which is wrong but since it say below the horizontal axis, will it be -315 degree?

2. Sep 25, 2008

### Buckshot23

I got the same for part a but I got something different for the impact angle.

the impact creates a triangle with x velocity and y velocity at impact. x velocity is constant at 2.68 m/s and I get 4.01 m/s for y velocity. Just finish it and you should get the right answer.

3. Sep 25, 2008

### Filenes

thanks alot.. now i gotta figure out why is the y velocity different .. thanks!