Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What was the cat's speed when it slid off the table?

  1. Feb 21, 2007 #1
    1. An autographed baseball rolls off of a 1.4 m high desk and strikes the floor 0.42 m away fro mthe desk.
    The acceleration of gravity is 9.81 m/s^2/ What was the cat's speed when it slid off the table? Anser in units of m/s.

    Since you want to find the initial velocity I used the formula:
    Vf^2=Vi^2+2ad I wasnt sure which distance to plug in there (1.4 or .42) I tried both distances and my answer was still wrong each time. You plug 9.81 as your 'a', your final velocity is 0 and you try to find your 'Vi'.
    So my equation is like this: 0^2=Vi^2+2x9.81x1.4 (or .42??)

    2. A cat chases a mouse across a 1.7 m high table. The mouse steps out of the way, and the cat slides off the table and strikes the floor 1.5m fro mthe edge of the table.
    The acceleration of gravity is 9.81 m/s^2. What was the cat's speed when it slid off the table? Answer in units of m/s/

    I tried to solve this one with the same equation I tried to solve the first one with, I also didnt know which distance to plug in and both my answers were wrong.
  2. jcsd
  3. Feb 21, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You should look in the vertcal and horizontal directions separately, and note that the final speed of the object is NOT zero just before it strikes the ground. Try solving for the time it takes the object to hit teh ground by looking in the vertical direction only, where the initial vertical speed is 0, since the object leaves the table horizontally, and gravity is acting downward. Then look in the horizontal direction. What is the acceleration in the horizontal direction?
  4. Feb 21, 2007 #3
    autographed baseball!o:)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook