There are 3 different types of energy. These 3 are fossil fuel, nuclear energy, and renewable energy. Most electricity is generated by ether wind, solar, or thermoelectric. Thermoelectric produces energy by burning coal,natural gas, and oil in a boiler.
Answer:

Explanation:
The mechanical work done by the load placed on a fiber if the fiber deforms by 3 nano-meter can be given in relation to the energy stored in a stretched fiber.
- We know according to the Hooke's law within the elastic limit the stress is directly proportional to the strain. The constant introduced is called stiffness constant defined as the magnitude of load applied for the deformation of one unit in the dimension of the object.
<u>The energy stored in a stretched fiber is equal to the work done:</u>

where:
k = stiffness constant
deformation in the fiber = 

Answer: 
Explanation:
Given
If an object reaches the topmost point i.e. it cannot travel beyond that point as its velocity is zero at the topmost point
As some velocity is needed to move the object, so velocity at topmost point is zero
Answer:
1977.696 J
Explanation:
Given;
Weight of the box = 28.0 kg
Force applied by the boy = 230 N
angle between the horizontal and the force = 35°
Therefore,
the horizontal component of the force = 230 × cosθ
= 230 × cos 35°
= 188.405 N
Coefficient of kinetic friction, μ = 0.24
Force by friction, f = μN
here,
N = Normal force = Mass × acceleration due to gravity
or
N = 28 × 9.81 = 274.68 N
therefore,
f = 0.24 × 274.68
or
f = 65.9232 N
Now,
work done by the boy, W₁ = 188.405 N × Displacement
= 188.405 N × 30
= 5652.15 J
and,
the
work done by the friction, W₂ = - 65.9232 N × Displacement
= - 65.9232 N × 30 m
= - 1977.696 J
[ since the friction force acts opposite to the direction of motion, therefore the workdone will be negative]
Answer:
yes ( true)
Explanation:
positive effects on all the body systems.