Let be the height of the tree. Then the total energy of the apple at the top of the tree will be eaual to it's potential energy:
where is the mass of the apple and is the free-fall acceleration due to gravity.
At the point 2.0 m above the ground the energy of the apple will be the sum of the kinetic and potential energies:
where is the speed of the apple at that point.
According to the conservation energy law:
Answer. h = 69.6 m.
Comments
Leave a comment