Answer:
1) We will have excess of electrons
2) The number of electrons transferred equals 
Explanation:
Part a)
Since we know that the charge transfer occurs by the transfer of electrons only as it is given that the carpet has acquired a positive charge it means that it has lost some of the electron's since electrons are negatively charged and if a neutral body looses negative charge it will become positively charged. The electron's that are lost by the carpet will be acquired by the feet of the human thus making us negatively charged.Hence we will gain electrons making us excess in electrons.
Part b)
From charge quantinization principle we have

where
Q = charge of body
n = no of electrons
e = fundamental charge
Applying values in the above equation we get

<u>Answer:</u>
The height of the cliff in meters = 27.44
<u>Explanation:</u>
The potential energy of a body is given by the expression, PE = mgh, where m is the mass of the body, g is the acceleration due to gravity value and h is the height of the body.
Here we have mass of rock = 13 kg
Potential energy = 3500 J
Acceleration due to gravity = 
Substituting 3500 = 13 * 9.81 * h
h = 27.44 meter
The height of the cliff in meters = 27.44
Answer:
Work done, W = −287500 Joules
Explanation:
It is given that,
Mass of the car, m = 920 kg
The car is travelling at a speed of, u = 90 km/h = 25 m/s
We need to find the amount of work must be done to stop this car. The final velocity of the car, v = 0
Work done is also defined as the change in kinetic energy of an object i.e.


W = −287500 Joules
Negative sign shows the work done is done is opposite direction.