Answer:
The intensity will be 1/9 as much.
Explanation:
The intensity of the light or any source is inversely related to the square of the distance.

Now according to the question the distance is increased by three times than,

Therefore,

Therefore the intensity will become 1/9 times to the initial intensity.
Answer:
21 miles
Explanation:
3 miles an hour for 7 hours
Its simply 7m*3m/hr=21 miles
Once all hydrogen is depleted the star begins to die
Answer:
W = 12.96 J
Explanation:
The force acting in the direction of motion of the sand paper is the frictional force. So, we first calculate the frictional force:
F = μR
where,
F = Friction Force = ?
μ = 0.92
R = Normal Force = 2.6 N
Therefore,
F = (0.92)(2.6 N)
F = 2.4 N
Now, the displacement is given as:
d = (0.12 m)(45)
d = 5.4 m
So, the work done will be:
W = F d
W = (2.4 N)(5.4 m)
<u>W = 12.96 J</u>