M1 v1 = (m1 + m2)v2.
All of the exponents should be lowered to the bottom right of the letters.
That n2 = 2*n1. That is, the index of refraction is twice as big in medium 2 since v=c/n
Answer:
C is the right answer.
Body massager uses electrical energy to move back and forth. In this sense, a motor is being used for the operation
Answer:
i don't know if this is good for you but
Explanation:
ignoring frictional air resistance (drag) the speed on return is the same as when it left the ground (5 m/s but in the opposite direction).
Note: this points out a good reason for not firing live bullets into the air..they will return somewhere and at the same speed.
However, if you take into account the atmospheric drag the reurn speed will be somewhat smaller (but in the case of a bullet, probably still lethal.) Drag depends on many factors and is difficult to calculate.
