The frequency of a sound is whatever frequency leaves the source. It doesn't change.
Voiced of swimmers at the pool don't change frequency in or out of the water. Only their speed and wavelength change.
Answer:195 J
Explanation:
Given
mass of ball 
ball leaves the hand with 
maximum height reached by ball 
Initial Mechanical energy when ball just leaves the hand


considering hand to be datum so h_1=0[/tex]
so Potential energy at ground is zero


Mechanical Energy at highest point

at highest Point velocity is zero



Decrease in Mechanical energy


They have different accelerations because of their masses. According to Newton's Second Law, an objects acceleration is inversely proportional to its mass. Therefore the object with the larger mass, in this case the gun, will have a smaller acceleration. In the same way, the less massive object, being the bullet, will have a higher acceleration.
Hope this helps :)
Answer:

Explanation:
Aceleration is a change on the velocity of the object in a given time.
For this case: the initial velocity is

and the final velocity is :

so, the change in velocity is:

and the change in time , according to the problem:

So, the aceleration is:

From the conservation of linear momentum of closed system,
Initial momentum = final momentum
Mass of the student, M = 59 kg
Mass of the laser boat, m = 42 kg
Initial speed of student + laser boat, u =0
Final speed of laser boat, v = 1.5 m/s
Final speed of the student = V
(M+m) u =M V +m v
0 = (59 kg) V + (42 kg) (1.5m/s)
V = - 1.06 m/s
Thus, the speed of the student is 1.06 m/s in the opposite direction of the motion of boat.