Answer:
This question is incomplete but the completed question is below
A ray of light parallel to the principal axis of a spherical mirror passes through its _____ after reflection.
(a) focus (b) pole (c) centre of curvature (d) imaginary centre of curvature
The correct option is (a)
Explanation:
After reflection, a ray of light will usually appear to diverge after they hit a spherical mirror, extending behind the mirror to meet at a point (called the focus or focal point) between the pole and the centre of curvature of this mirror. Hence, option a is the correct option.
Answer:
As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is what meteorologists and mountaineers mean by "thin air." Thin air exerts less pressure than air at a lower altitude
Answer:
It would take 16.7 s for the work to be done by the engine.
Explanation:
From the question, given: Power = 390.3 kW
Work to be done = 6.5 x 
J
But, power and work done with respect to time, has a relationship of:
Power = 
So that,
time = 
Thus,
time = 
= 16.6539
time = 16.7 s
Time required is 16.7 seconds.
Thus, it would take 16.7 s for the work to be done by the engine.
Answer:
Water
Explanation:
Because it does not conduct much energy.
