(a) 
According to Newton's second law, the force experienced by each balloon is given by:
F = ma
where
m = 0.021 kg is the mass
a = 1.1 m/s^2 is the acceleration
Substituting, we found:
The electrostatic force between the two balloons can be also written as
where
k is the Coulomb's constant
Q is the charge on each balloon
r = 16 m is their separation
Since we know the value of F, we can find Q, the magnitude of the charge on each balloon:
(b) 
electrons
The magnitude of the charge of one electron is
While the magnitude of the charge on one balloon is
This charge can be written as
where N is the number of electrons that are responsible for this charge. Solving for N, we find:
Answer:
Explanation:
Let the initial velocity of small block be v .
by applying conservation of momentum we can find velocity of common mass
25 v = 75 V , V is velocity of common mass after collision.
V = v / 3
For reaching the height we shall apply conservation of mechanical energy
1/2 m v² = mgh
1/2 x 75 x V² = 75 x g x 10
V² = 2g x 10
v² / 9 = 2 x 9.8 x 10
v² = 9 x 2 x 9.8 x 10
v = 42 m /s
small block must have velocity of 42 m /s .
Impulse by small block on large block
= change in momentum of large block
= 75 x V
= 75 x 42 / 3
= 1050 Ns.
Answer: from the information given, the velocity of the water will decrease but the pipe size will remain the same.
This can be proved with bernoulli's equation.
Explanation: careful analysis of the system using bernoulli's equation of flow is shown in the image attached
This is something u are going to have to do
