A beam of laser is directed at a reflecting surface put on the moon when the beam of laser is reflected a receiver on the each measure the time since the beam was sent till it was received. Laser is simply light so it has constant velocity in vacuum ~ air (c = 3 x 10^8 m/s)
to find the distance:
t : time measured between launching the beam and receiving it
d : distance
d = ct
Each person is 80kg. 320/4
To solve this problem it is necessary to apply the fluid mechanics equations related to continuity, for which the proportion of the input flow is equal to the output flow, in other words:

We know that the flow rate is equivalent to the velocity of the fluid in its area, that is,

Where
V = Velocity
A = Cross-sectional Area
Our values are given as



Since there is continuity we have now that,






Therefore the speed of the water's house supply line is 0.347m/s