Posted by kelsey on Wednesday, October 8, 2008 at 12:42am.
A 0.26 kg rock is thrown vertically upward from the top of a cliff that is 35 m high. When it hits the ground at the base of the cliff the rock has a speed of 28 m/s.
(a) Assuming that air resistance can be ignored, find the initial speed of the rock.
(b) Find the greatest height of the rock as measured from the base of the cliff.

physics..help PLEASE!  drwls, Wednesday, October 8, 2008 at 1:52am
(a) When air resistance can be ignored, the sum of potential and kinetic energy is constant. That means that V^2/2 + g h is constant, where h is the height measured from any reference plane. (The mass M cancels out). Use that fact to solve for the initial velocity Vo.
28^2/2 = Vo^2/2 + g*35
(b) At the greatest height, V = 0. use the same approach to solve for Hmax
Answer This Question
Related Questions
 physics  c) A 0.26kg rock is thrown vertically upward from the top of a cliff ...
 physics  A 0.26 kg rock is thrown vertically upward from the top of a cliff ...
 PHYSICS  A 0.26kg rock is thrown vertically upward from the top of a cliff ...
 Physics  A 0.26kg rock is thrown vertically upward from the top of a cliff ...
 Physics  A 0.26 kg rock is thrown vertically upward from the top of a cliff ...
 physics  A rock is thrown vertically upward from the edge of a cliff. The rock ...
 physics  A rock is thrown vertically upward from the edge of a cliff. The rock ...
 Math  For this problem, a person standing on the edge of a cliff throws a rock ...
 Physics  A boy kicks a rock off a cliff with a speed of 19.4 m/s at an angle of...
 Physics  A boy kicks a rock off a cliff with a speed of 15.5m/s at an angle of ...
More Related Questions