The speed of sound will be different if which of the following happens?
-the sound travels through different materials.
-the sound gets louder and louder.
-the source of the sound is moving.
-the source of the sound is heated.

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

What is the freezing point of radiator fluid that is 50% antifreeze by mass? kf for water is 1.86 ∘c/m.

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?