Answer:
12.5m/s
Explanation:
(Assuming the question was asking for the speed just before it hit the ground)
We can use the first key equation of accelerated motion
Vf^2 = Vi^2+2aΔd
Vf^2 = 0 + 2(9.8)(8) (plugged in values, initial velocity is 0 since the ball was at rest)
Vf^2 = 156.8
Vf = 12.5 (squared both sides)
Answer:
So the repulsive force between the pith ball will be 
Explanation:
We have given that the pith ball have the equal charge q = -40 nC =
Distance between the charges = 10 cm =0.1 m
According to coulombs law 

So the repulsive force between the pith ball will be 
Answer:
C) Pnew=Poriginal/9
Explanation:
From the given conditions:
Original area, 
New area of the barrel bottom panel after increasing by a factor of 3:

On increasing the radius the area now becomes:


As we know that there will be no increase in the down-force since the height remains constant.
Pressure is given as:

∴New pressure:

