Power is the amount of work done over a period of time. If you will put that into an equation, the formula of power will be:
P = W/t
Where:
P = power
W=work
t = time
Your problem already provides you with work and time so all you need to do is divide:
P = W/t
P = 50J/30s
P = 1.67 W
Answer:
50 J
Explanation:
The net force acting on the box is given by the algebraic sum of the two forces, so:
The net work done on the box is equal to (assuming the net force is parallel to the displacement of the object)
where
F = 5 N is the net force on the object
d = 10 m is the displacement of the object
Substituting,
There are multiple reasons for this. First of all, water is available in almost every place on the Earth. It doesn't pollute the air, doesn't cause health use and is easily handle.
Other factor is the fact that water has a really high specific heat. This means that water, and more specifically steam, can aborb and transport more energy. A lower heat capacity would imply the need to boil more of the liquid to obtain the same amount of energy. This combine with the fact that water expands at a large rate when boiling, combine with everything mentioned previously, and you get a liquid with all the characteristics that a efficient turbine requires to work.
Answer:
She does a work of 689.44 J in the snow.
Explanation:
A force is said to do work when it alters the state of motion of a body. The work of the force on that body will be equivalent to the energy needed to move it.
In other words, Work is a form of energy transmission between bodies. In order to carry out work, a force must be exerted on a body and it must move.
The work is equal to the product of the force times the distance and the cosine of the angle that exists between the direction of the force and the direction that the moving point or object travels:
W= F*d* cos Ф
Work W is measured in joules (J), force is measured in newtons (N), and displacement in meters (m).
In this case:
- F= 180 N
- d=5 m
- Ф= 40 degrees
Replacing:
W= 180 N*5 m* cos 40
Solving:
W= 689.44 J
<u><em>She does a work of 689.44 J in the snow.</em></u>
Answer:
Work Done = 67.5 J
Explanation:
First we find the value of spring constant (k) using Hooke's Law. Hooke's is formulated as:
F = kx
where,
F = Force Applied = 450 N
k = Spring Constant = ?
x = Stretched Length = 30 cm = 0.3 m
Therefore,
450 N = k(0.3 m)
k = 450 N/0.3 m
k = 1500 N/m
Now, the formula for the work done in stretching the spring is given as:
W = (1/2)kx²
Where,
W = Work done = ?
k = 1500 N/m
x = 70 cm - 40 cm = 0.3 m
Therefore,
W = (1/2)(1500 N/m)(0.3 m)²
<u>W = 67.5 J</u>
