What will happen if a spoon measuring 5 °C is placed into a glass of water measuring 20 °C? A. Heat will move from the water to the spoon until the spoon reaches 20 °C.
B. Heat will move from the spoon into the water until both are balanced at 25 °C.
Heat will move from the spoon into the water until the temperatures of both are balanced
at 15 °C.
C.
D.
Heat will move from the water to the spoon until the temperatures of both are balanced
between 5 °C and 20 °C.

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!

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

Aplane travels 1000 miles in 5 hours .what is the planes average speed?