The pendulum in a clock gradually slows down and stops moving after a while. A student states that its a loss of mechanical energy is evidence that energy is not always conserved. which two statements offer evidence that the clocks energy is conserved?

A. Friction between its moving parts transforms some of the pendulums mechanical energy into
other forms of energy

B. Conservation of energy happens only when the parts of the clock are oiled to reduce friction.

C. conservation of energy occurs because
the clocks matter is also conserved

D. the pendulum stops moving because all of its mechanical energy has been transformed into thermal energy and sound energy.

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Astate of matter all that has define volume and can flow is a(n)

Suppose while hauling rocks, you accidentally drop one. it breaks apart in flat, planar sections. what type of rock did you just drop? 20 points