If the kinetic and potential energy in a system are equal, then the potential energy increases

How many seconds does it take a pebble released from rest off a bridge to fall 29.4 m ? what is the pebble's speed when it has fallen 29.4 m ?

Acrow drops a 0.11kg clam onto a rocky beach from a height of 9.8m. what is the kinetic energy of the clam when it is 5.0m above the ground? what is its speed at that point?

Argon is adiabatically compressed from an initial volume of 16 liters to a final volume of 2 liters. by what factor do the following quantities change? do they increase or decrease? (a) the rms speed (b) the thermal energy of the gas (c) the molar specific heat cv (d) the pressure