Work And Energy Test - 2

In an inclined plane the distance travelled by an object is more but the force required is less. Since when work is done energy is conservative, hence, we gain in terms of force.

Kilowatt hour is the unit of energy which is equal to 3.6 × 10⁶ J.

P = F.v
Power = constant (c)
F.v = cF.s/t = c
m.a.s/t = c

m.a.s = ct
a.s = c/m x t
a.s = bt (c/m = b)
a = v/t

(v/t)s = bt
vs = bt²

s/t x s = bt²
s² = bt³
s = bt^3/2

A thermoelectric generator is a solid state device which converts the thermal energy into electrical energy. It is based on the "Seebeck effect".

The Seebeck effect is a phenomenon in which a temperature difference between two dissimilar metals or semiconductors produces a voltage difference between the two substances. When one junction is kept hot and the other junction is kept cold, heated electrons flow towards the cooler one and direct current (DC) flows through that circuit.

The voltages produced by the Seebeck effect are small, usually only a few microvolts per kelvin of temperature difference at the junction.

Photovoltaic cell is a semiconductor device which converts the light energy into electric energy. It works based on "photovoltaic effect".

The photovoltaic effect can be defined as being the appearance of a potential difference (voltage) between two layers of a semiconductor slice, in which the conductivities are opposite, or between a semiconductor and a metal, under the effect of a light.

A bent bow possesses potential energy. This potential energy is then converted to kinetic energy of the arrow.

E = 1/2 kx²
For 20 turns E is proportional to (20)²
E ∝ 400
For 10 turns E is proportional to (10)²
E ∝ 100
The energy is one fourth of the first one so secondly it will run for 7.5 hours