Answer:
Explanation:
The apparent brightness follows an inverse square law, therefore we can write:
where I is the apparent brightness and r is the distance from the Sun.
We can also rewrite the law as
(1)
where in this problem, we have:
apparent brightness at a distance
, where
million km
We want to estimate the apparent brightness at , where
is ten times
, so
Re-arranging eq.(1), we find :
Answer:
B.The linear velocity of the gears is the same. The linear velocity is 432π centimeters per minute.
Explanation:
As we know that the small gear completes 24 revolutions in 20 seconds
so the angular speed of the smaller gear is given as
Now we know that the tangential speed of the chain is given as
so we have
Since both gears are connected by same chain so both have same linear speed and hence correct answer will be
B.The linear velocity of the gears is the same. The linear velocity is 432π centimeters per minute.