Answer:
Given,
mass of man = 100 N = 10 kg
height = h = 25m
since the man does not move anything with his force, work done by him is zero
work done on the man = gain in potential energy
P.E=mgh
P.E=10×9.8×25
P.E=2.45KJ
Explanation:
so, potential energy gained by man is 2.45 KJ
Answer:

Explanation:
The work done on the capacitor is equal to the difference in potential energy stored in the capacitor in two different cases.
The potential energy is given by the following formula:

where C can be calculated using the plate separation and area.

Therefore, the potential energy in the first case is

In the second case:

The permittivity of the air is very close to that of vacuum, which is 8.8 x 10^-12.
So, the difference in the potential energy is

Answer:
the cost of operating the light bulb is 72 cents.
Explanation:
Given;
cost of electricity, C = 6 cents / kW.h
power of light bulb, P = 100 W
time of light power consumption, t = 4 hours per day for 30 days
total time = 4 hours x 30 = 120 hours
Power consumed by the light bulb is calculated as;
P = 100 x 120 = 12000 w.h = 12 kW.h
Cost of power consumption = 6 cents/kWh x 12 kWh
= 72 cents
Therefore, the cost of operating the light bulb is 72 cents.
Answer:
Explanation:
Angular velocity ω = 2π / T = 2 x 3 . 14 / (4 x 60 ) = .026 rad / s.
d = D Sin ( ωt + θ ) where D = amplitude = 11 m θ = initial phase.
-11 = 11 sin ( 0 + θ ) = sin θ = -1 , θ = - π /2
So, d = D Sin ( ωt - θ )
d = 11 Sin ( .026 t - π /2 ) is the required equation.
Elaborate rehearsal involves organizing and breaking down information into easier groups to expand capacity. Rehearsal is the verbal repetition of information. These techniques are especially important for the improvement of long-term memory.
Six strategies of elaborate rehearsal are:
1. Rephrase information into your own words.
2. Create your own study questions and answer them.
3. Use images to help you.
4. Group terms that are of the same topic together.
5. Use a mnemonic strategy.
6. Space our your learning and don't try to cram in on sitting.