A student determined to test the law of gravity for himself walks off a skyscraper 900ft tall, stopwatch in hand and starts to feefall (velocity initial equals 0 ). Five seconds later superman arrives at the scene and dives off the roof to save him.
A. what must be supermans initial velocity if he is to catch the student just before he hits the ground?
B. What must be the height of the building so that even superman can not save him? (assume supermans acceleration to be that of a free falling body)
PLease HElp!!
2007-10-09 14:05:37 · 1 answers · asked by bubblebee 2 in Science & Mathematics ➔ Physics
Where is a bloody phone booth when you need one!
Gee I thought even Supper Man had inertia.
Ss=0.5gt^2
Ssm=V0(t-5) + 0.5g(t-5)^2
Just before the ground Ss=Ssm
and t= sqrt(2Ss/g)
A)V0=(Ss - 0.5g(t-5)^2 )/(t-5)
B) For Superman to be successful
Ss - 0.5g(t-5)^2 >=0
Ss >= 0.5g(t-5)^2
2007-10-10 05:03:32 · answer #1 · answered by Edward 7 · 1⤊ 0⤋