Answer:
D
Explanation:
Because it is the principle of conservation of energy which is proved and verified
When a layer of cold air close to the ground is covered by a layer of warmer air, sound waves traveling upward may be bent, or refracted, by the difference in temperature and redirected toward the ground.
Answer:
Explanation:
The stunt will likely sustain serious injury in case of concrete blocks because the average force acting on the person will be more because concrete blocks do not squeeze to provide more time for the force to act on the body instead it acts for a small amount of interval.

As impulse is constant so time requires to act force on the body is more as compared to concrete block and thus average force in mattress case is less.
Answer:

Explanation:
Use the velocity formula to solve

In this question, you are given velocity
, and you are given a distance,
. Time in this question is what you'll need to find.
Start by rearranging the velocity formula, to isolate for t.

Start by multiplying both sides by t

Then divide both sides by v.

Now that you've isolated for time, sub in your values and calculate.
