How are Potential energy and Kinetic energy used in catapults?

Question

How are Potential energy and Kinetic energy used in catapults?

and or in Bicycles?

Answer 1

meh. No tmuch to say for stuff that's already been said. Friction (air resistance) shouldn't slow down a huge stone with such a chaotic cross-section as a rock. For a sophisticated answer, I would take into account friction but mention that b/c of cross-sectional area being so chaotic it shouldn't matter that much.
BTW what's not mentioned is that PE is stored in the tension in the string, and the string's restoring force is what moves the catapult launch-arm-thingy which stores KE within the rock. But the rock is moved by the normal force of the huge cup-thingy acting on the rock, so yeah, a bit of energy is lost since normal force is non-consevative. Trust me, I know what I'm saying, even though i don't sound technical. So, to summarize:
(a bit of) energy is lost in:
-Normal force
-Friction (air resistance)
PE is stored in the tension in the string/rope, which has a restoring force
KE is when the rock gets moved b/c of the normal force acting on the rock and when it gets launched in the air.
Pretty sure on the normal force stuff, sure on everything else.

Answer 2

Kinetic energy is used to pull back the catapult, and pretty much get the spring ready for launch. The spring containts elastic potential energy. That eleastic potential energy converts to kinetic energy, and whatever is launched gains gravitational potential energy while losing kinetic energy, until it reaches its max height. At its max height it has the least amount of kinetic energy, but the greatest potential energy. As it falls in loses potential energy and gains kinetic energy.

If there are no Non-conservative forces (like friction, or air resistance) then at any time in that cycle the kinetic energy used to load the spring will equal the combined potential and kinetic energies at any time.

Answer 3

ha! Not sure about catapults, but potential energy describes the possible energy which the device has not yet released.... what it is capable of. Kinetic energy is 'energy in motion' - the measurement of the catapulted objects mass and velocity...
in a nutshell: potential is the catapult loaded, but at rest. The kinetic is the catapult in action. (Layman's terms!)

Answer 4

potential energy is stored while the object to be catapulted is at rest... as the object is catapulted, this energy is converted to kinetic energy

Answer 5

PT is used when the catapult is at rest and KC is used when PC is lost.

Answer 6

he aw