Explanation:
The energy stored in coal is directly form the sun which is solar energy. This energy are preserved in carbon atoms and they originate from the life processes of a plant.
- Plants carry out photosynthesis and produce their energy by this process.
- Green plants have special adapted structures by which they trap solar energy from the sun and use it to produce their own food.
- The food is used by plant for nutrition and life activities.
- In essence the solar energy is converted to chemical energy in plants.
- To form coal, when plants are rapidly buried their organic matter is preserved from decay by combination with oxygen.
- More burial preserves the complex molecules that have stored during photosynthesis.
- The carbon eventually aggregates for coal.
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Answer:
Explanation:
Far point = 17 cm . That means he can not see beyond this distance .
He wants to see at an object at 65 cm away . That means object placed at 65 has image at 17 cm by concave lens . Using lens formula
1 / v - 1 / u = 1 / f
1 / - 17 - 1 / - 65 = 1 / f
= 1 / 65 - 1 / 17
= - .0434 = 1 / f
power = - 100 / f
= - 100 x .0434
= - 4.34 D .
Answer:
a) 1504.8 J
b) 991.76 J
c) 0J
d) 0J
Explanation:
(a) The work done by the force P on the box is given by the following formula:
P: applied force = 171N
x: distance in which the for P is applied = 8.80m
you replace the values of P and x and obtain:
(b) The work don by the friction force is:
μ = coefficient of kinetic friction = 0.250
M: mass of the box = 46.0kg
g: gravitational constant = 9.8 m/s^2
(c) The Normal force is
but this force does not do work on the box because the direction is perpendicular to the direction of the force P.
(d) the same as before:
