A heavy rock and a light rock are dropped from the same height and experience no significant air resistance as they fall. Which of the following statements about these rocks are correct? a. Just as they are about to reach the ground, the heavier rock has more kinetic energy than the lighter rock.
b. The moment they were released, both rocks had the same amount of gravitational potential energy.
c. Both rocks have the same kinetic energy when they reach the ground.
d. The heavier rock reaches the ground before the lighter rock.
e. Both rocks different acceleration as they are about to reach the ground

What kind of simple machine is a catapult?

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton