F=ma
F = 148×(85-35)÷20
F = 148×(50÷20)
F = 148×2.5
F = 370N
Explanation:
Drinking water requirement in town 2.0 m^3/s of water per second
nitrate in local well nitrate per 15 
of water
nitrate in distant reservoir 
Let the flow rate of well
flow rate of reservoir 
Drinking water requirement is 
or 
therefore, the total flow of drinking water
The difference between the above velocities is that they exist in opposite direction of each other. or it can be said that they are negative vectors of each other.
Electromagnetic radiation is an energy that is known as light. so electromagnetic radiation will have the same speed as the speed of light which is 3 x 10^8 m/s. so the distance it travel at 55 x 10^-6 s is:
D = ( 3 x 10^8 m/s ) ( 55 x 10^-6 s )
D = 16500 m
C) total linear momentum of the ball and cannon is conserved.
Basically it happens that in the beginning before there is a momentum acting on the two bodies, these are a unique system. Here the total momentum of the System is 0. However, when the positive momentum of the cannonball is added, the system will be immediately affected by a negative momentum which will pull back the cannon. Could this be extrapolated as a condition of Newton's third law.
