Suppose a mechanical wave is traveling through medium A. When the wave enters medium B, it speeds up. Which of the following statements is true about medium A and medium B? The answers:
A. Medium A is a solid and medium B is a gas.
B. Medium A is a liquid and medium B is a solid.
C. Medium A is a gas and medium B is a vacuum.
D. Medium A is a vacuum and medium B is a liquid.

Which of the following is the result of the nuclear weak force? the instability of large nuclei the repelling force between positively charged protons the structure of the atom certain types of nuclear decay

Current from a charged capacitor lights a bulb. as time goes on the brightness of the

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?