It becomes a positive Iron
Answer:
(a) 43.2 kC
(b) 0.012V kWh
(c) 0.108V cents
Explanation:
<u>Given:</u>
- i = current flow = 3 A
- t = time interval for which the current flow =

- V = terminal voltage of the battery
- R = rate of energy = 9 cents/kWh
<u>Assume:</u>
- Q = charge transported as a result of charging
- E = energy expended
- C = cost of charging
Part (a):
We know that the charge flow rate is the electric current flow through a wire.

Hence, 43.2 kC of charge is transported as a result of charging.
Part (b):
We know the electrical energy dissipated due to current flow across a voltage drop for a time interval is given by:

Hence, 0.012V kWh is expended in charging the battery.
Part (c):
We know that the energy cost is equal to the product of energy expended and the rate of energy.

Hence, 0.108V cents is the charging cost of the battery.
a) Work done = Net Kinetic Energy
= 1/2 x 50 kg x ((12m/s)^2 - (3m/s)^2)
= 0.5 x 50 Kg x (144 -9)(m/s)^2
= 3375 Kg (m/s)^2
b) Force = mxa
a = 120 N/50 Kg = 2.4 m/s^2
Using newtons third law of motion, we get-
V^2 - U^2 = 2 x a x S
S= (12^2-3^2)m^2/s^2/(2 x 2.4 m/s^2)
= 28.125 m
But the fact is that an accelerating object is an object that is changing it’s velocity.. for this reason , it can be safely concluded that an object moving in a circle at constant speed is indeed accelerating. It is accelerating because the direction of the velocity vector is changing .