1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Dropped Tennis Ball

  1. Jan 29, 2009 #1
    1. The problem statement, all variables and given/known data
    A 0.4 kg tennis ball is dropped from rest at a height of 6.2 m onto a hard floor.


    2. Relevant equations
    a) What is the speed of the ball at the instant of contact with the floor?
    v=(2gx)^.5
    v=(2*9.81*6.2m)^.5
    =11 m/s
    b) A flash photograph shows that the ball is compressed a maximum of 0.6 cm when it strikes the floor.
    Assuming that the acceleration of the ball is constant during its contact with the floor, what force does the floor exert on the ball?

    3. The attempt at a solution
    So for this question, i used the velocity as a function of position equation: V^2=Vo^2+2a(Delta)y
    Then i solved for a a=v^2-Vo^2/2(Delta)y
    a=11^2-0/2(6.194)=9.76 m/s^2
    F=ma=.4kg(9.76 m/s^2)=3.9 N
    But this answer is incorrect. I think i have the right idea, maybe i am using the wrong equation or did i make a mistake?
     
  2. jcsd
  3. Jan 29, 2009 #2
    For part a) what is the easiest way is energy relations. You got the equations on this part. Double check your numbers, though. I haven't a calculator, but it's a good idea.

    For part b), there is a better relation. Ask yourself what the center of mass is doing on impact. And then think about momentum.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Dropped Tennis Ball
  1. Tennis Ball Drop (Replies: 6)

  2. Tennis Ball Drop II (Replies: 2)

  3. Dropping a tennis ball (Replies: 3)

Loading...