Hello!
The speed of a falling ball is downwards, where g is the gravity acceleration. The height of a falling ball is
where is the initial height.
A ball strikes the ground when H(t)=0, so
and the speed will be This is the answer to the first part.
The kinetic energy before the strike is at the end of the re-bouncing it will be zero. The change...
Hello!
The speed of a falling ball is downwards, where g is the gravity acceleration. The height of a falling ball is
where is the initial height.
A ball strikes the ground when H(t)=0, so
and the speed will be This is the answer to the first part.
The kinetic energy before the strike is at the end of the re-bouncing it will be zero. The change of the potential energy will be
, where
is the maximum height after the re-bouncing. So
or
This is the answer for the second part.
That said, the first part could be solved quickier using energy considerations (potential energy becomes kinetic), and the second - considering the potential energy before the fall :)
No comments:
Post a Comment