Solve for the time and initial velocity of a ball rolling off a table?"

  • Thread starter Thread starter TS656577
  • Start date Start date
  • Tags Tags
    Physics
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
5 replies · 3K views
TS656577
Messages
62
Reaction score
0
[SOLVED] Physics again

Homework Statement



A small ball rolls horizontally off the edge of a tabletop that is 1.19 m high. It strikes the floor at a point 1.78 m horizontally away from the edge of the table. (a) How long is the ball in the air? (b) What is its speed at the instant it leaves the table?

Homework Equations


x=vcos(x)t
y=vsin(x)t- .5gt^2


The Attempt at a Solution



I believe those are the right equations that I need, but I have two unknowns in the equation, velocity and time.
 
Physics news on Phys.org
The only other equation that I could maybe see using is y=(tan(*)x - (gx^2)/2(vcos(*)^2)
 
If the ball were simply dropped from a height of 1.19 m, how long would it take to fall?
 
TS656577 said:
This may sound stupid, but I have no idea...

[tex]y=ut+\frac{1}{2}gt^2[/tex]
(u=initial velocity)

Vertically...what is the height it falls from? Is there any initial vertical velocity?
 
Hmmm since there is no initial velocity, then the "ut" in essence cancels out to 0, thus, solving for t I got, .493 seconds.