Beer Mug 2D Problem: Vel & Dir Calculation

[GlobalDuty]

Homework Statement

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 0.40 m from the base of the counter. The height of the counter is 0.730 m.
(a) With what velocity did the mug leave the counter?
(b) What was the direction of the mug's velocity just before it hit the floor?

The Attempt at a Solution

For part A: I calculated the time it took for the beer mug to hit to floor vertically. Vyf-Vyi/g = t
for time i got .287 and so i did displacement/time= velocity which is:
.40/.287 to get 1.4 which is wrong.

 

[ideasrule]

How did you get Vyf?

 

[GlobalDuty]

i did Vyf^2 = Vyi^2 +2a(yf-yi)
that is squaring the initial velocity of Y which is zero and adding 2(accelaration)(0-.730)

 

[ideasrule]

In that case, you just made a calculation error. Try calculating again; t isn't 0.287 s.

 

[GlobalDuty]

thank you, i got the right answer. but isn't there a quicker way to do these types of problems?