Calculate the height of a cliff if it takes 2.35 s for a rock to hit the ground when it is thrown straight up from the cliff with an initial velocity of 8.00 m/s. express your answer in m to at least 3 significant digits.

We have the equation of motion , , where s is the displacement, u is the initial velocity, t is the time taken and a is the acceleration.

In this case s = ?

We have u = 8 m/s, t = 2.35 seconds and a = -9.81

Substituting

Here - ve sign means below the level of cliff it is 8.29 meter deep

So height of cliff = 8.29 meter

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )