Answer: False
Explanation:
Relative to the concept of radiations, a black body is an object capable of absorbing any form of electromagnetic radiation irrespective of its frequency or angle of incidence when incident on such object.
However, the same cannot be said about real bodies as real bodies are those which reflect all rays incident on them completely and uniformly in all directions.
One very important characteristic of black bodies is that they are ideal emmiters.
The concept of emmisivity is brought about by the existence of real bodies .
This is due to the fact that they are only able to emit radiation at a fraction of the black body energy levels.
Please note that by convention, the emmisivity of a real body is always less thaan 1.
As such they are not able to emit as much radiation as a black body at the same temperature.
<h3>
Answer: 22.5 m/s</h3>
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Work Shown:
acceleration = ( finalVelocity - initialVelocity )/(change in time)
1.5 = (60 - x)/(25)
1.5*25 = 60-x
37.5 = 60-x
x = 60-37.5
x = 22.5
The initial velocity is 22.5 m/s
Under normal lighting conditions, most diamonds appear to be colorless the naked eye. Many consumers think that all diamonds are colorless, however, in reality, they come in a wide range of colors. Actualcolor differences are very subtle.
Answer:
first lens v = 48 cm
second lens v = -15.6 cm
magnification = 1.67
final image is virtual
and final image is upright
Explanation:
given data
distance = 16 cm
focal length f1 = 12 cm
focal length f2 = 10.0 cm
to find out
location of the final image and magnification and Type of image
solution
we apply here lens formula that is
1/f = 1/v + 1/u .....................1
put here all value and find v for 1st lens
1/12 = 1/v + 1/16
v = 48 cm
and find v for 2nd lens
here u = 20- 48 = -28
- 1/10 = 1/v - 1/28
v = -15.6 cm
and
magnification = first lens (v/u) × second lens ( v/u)
magnification = (-15.6/-28) × ( 48/16)
magnification = 1.67
so here final image is virtual
and final image is upright
