Answer:
a) 
b) 
Explanation:
Given;
- depth of the water-tank,

- length of the pipe,

- inclination of the pipe from the horizontal,

a)
Now the effective vertical height of the water column from the free surface of the water to the bottom of the pipe at house:



Now the pressure due to effective water head:

where:
density of the liquid, here water
acceleration due to gravity
height of the liquid column


b)
Now the height of water corresponding to this pressure will be the same as the effective water head by the law of conservation of energy.

Answer:
0.15m/s
Explanation:
Momentum p = mv, must be conserved if there are no external forces acting on the system. Since there are only internal forces acting between the bullet and the gun, momentum must be conserved.
The total momentum before the gun is fired:

The total momentum after the gun is fired, must also be zero:

Solving for v:

The recoil speed is the absolute value of the velocity.
Answer:
.......................
Explanation:
A net force = unbalanced force. If however, the forces are balanced (in equilibrium) and there is no net force, the object will not accelerate and the velocity will remain constant.
A.
The planet contains matter and energy so it is a system.
Answer: 4.5 V
Explanation:
Given
The voltage of each cell is 1.5 V
If they are connected end to end their potential added to give a higher potential i.e. 1.5+1.5+1.5=4.5 V