Hey i dont have an answer but i need the points for finals today. Thank you
Given: The mass of stone (m) = 0.5 kg
Raised from heights (h₁) = 1.0 m to (h₂) = 2.0 m
Acceleration due to gravity (g) = 9.8 m/s²
To find: The change in potential energy of the stone
Formula: The potential energy (P) = mgh
where, all alphabets are in their usual meanings.
Now, we shall calculate the change in potential energy of the stone
Δ P = P₂ - P₁ = mg (h₂ - h₁)
or, = 0.5 kg ×9.8 m/s² ×(2.0 m - 1.0 m)
or, = 4.9 J
Hence, the required change in the potential energy of the stone will be 4.9 J
Answer:
(a) 
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:

where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:

(b)
Now, for 90% radiator blackbody at 2000 K:

<u>P = 0.816 Watt</u>
Answer:
The x-component of
is 56.148 newtons.
Explanation:
From 1st and 2nd Newton's Law we know that a system is at rest when net acceleration is zero. Then, the vectorial sum of the three forces must be equal to zero. That is:
(1)
Where:
,
,
- External forces exerted on the ring, measured in newtons.
- Vector zero, measured in newtons.
If we know that
,
,
and
, then we construct the following system of linear equations:
(2)
(3)
The solution of this system is:
, 
The x-component of
is 56.148 newtons.
The water cycle is all about storing water and moving water on, in, and above the Earth. Although the atmosphere may not be a great storehouse of water, it is the superhighway used to move water around the globe. Evaporation and transpiration change liquid water into vapor, which ascends into the atmosphere due to rising air currents. Cooler temperatures aloft allow the vapor to condense into clouds and strong winds move the clouds around the world until the water falls as precipitation to replenish the earthbound parts of the water cycle. About 90 percent of water in the atmosphere is produced by evaporation from water bodies, while the other 10 percent comes from transpiration from plants.
There is always water in the atmosphere. Clouds are, of course, the most visible manifestation of atmospheric water, but even clear air contains water—water in particles that are too small to be seen. One estimate of the volume of water in the atmosphere at any one time is about 3,100 cubic miles (mi3) or 12,900 cubic kilometers (km3). That may sound like a lot, but it is only about 0.001 percent of the total Earth's water volume of about 332,500,000 mi3 (1,385,000,000 km3), If all of the water in the atmosphere rained down at once, it would only cover the globe to a depth of 2.5 centimeters, about 1 inch.