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
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.
 
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?
 
This may sound stupid, but I have no idea...
 
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.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
Replies
6
Views
3K
Replies
14
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 38 ·
2
Replies
38
Views
5K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
3
Views
2K