Answer:
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its Stated velocity. Having gained this energy during its acceleration, the body maintains the kinetic energy unless it's speed changes.
(or in short)"Energy which a body possesses by virtue of being in motion"
Answer:
Explanation:
a ) The angle between the polarization axis of two adjecent sheet
= 90 / 3 = 30 degree.
The formula for intensity of polarised light from unpolarised light ( first transmission
I₁ = I₀ /2
I₀ is intensity of unpolarised light and I₁ is intensity of light after first time polarization .
The relation of I₁ and I₂ is as follows
I₂ = I₁ cos²30
= I₀/2 x3/4
=3 I₀/8
Relation between I₃ and I₂ is as follows
I₃ = I₂ cos²30
= 3I₀ / 8 x 3/4
= 9 I₀ / 32
= 0 .28 I₀
In case of stack of 4 plates
angle between two plates = 90/4 = 22.5 degree
I₁ = I₀ /2
I₂ = I₁ cos²22.5
= I₀ /2 x .85
I₃ = I₂ cos²22.5
= I₀ /2 x .85 x .85
= .36 I₀
Na is in the first column on the periodic table so therefore it would have 1 valence electron
D 1
<span>C) Just before he starts to fall to the ground
Remember that "gravitational potential energy" is the energy the object potentially has if it were to drop from the current height. So let's look at the options and see what's correct.
A) When he initially lands
* He's currently near the lowest height. So his gravitational potential energy is quite low. So this is the wrong choice.
B) As he runs forward to plant the pole
* He's on the ground. So has almost no height. So almost no gravitational potential energy. So this too is wrong.
C) Just before he starts to fall to the ground
* Ah. He's at his maximum height. So his potential gravitational potential energy is maximized. This is the correct choice.
D) After take-off as the pole expands and lifts the vaulter toward the bar
* He's at a low height. So once again, this is a bad choice.</span>
<span>Window glass is a much better conductor of thermal energy than a plastic foam (styrofoam) cup.
The exact "thermal conductivity" rating of window glass depends on its mineral composition .
The thermal conductivity of styrofoam is very low, because it traps air in small pockets, and air has a very low thermal conductivity. That is why styrofoam is widely used as insulation.</span>
