Explanation:
The given data is as follows.
q = 6.0 nC = 
inner radius (r) = 1.0 cm = 0.01 m (as 1 cm = 100 m)
So, there will be same charge on the inner surface as the charge enclosed with an opposite sign.
Formula to calculate the charge density is as follows.
.......... (1)
Since, area of the sphere is as follows.
A =
........... (2)
Hence, substituting equation (2) in equation (1) as follows.

=
= 
or, = 4.77 
Thus, we can conclude that the resulting charge density on the inner surface of the conducting sphere is 4.77
.
To answer this question, it helps enormously if you know
the formula for momentum:
Momentum = (mass) x (speed) .
Looking at the formula, you can see that momentum is directly
proportional to speed. So if speed doubles, so does momentum.
If the car's momentum is 20,000 kg-m/s now, then after its speed
doubles, its momentum has also doubled, to 40,000 kg-m/s.
From a to b speed is 600+40 = 640
from b to a speed is 600-40 = 560
let t be the number of hours of flight. This would mean it would have traveled a distance of 640 miles and the distance yet to travel is 2400-640t
Time left will be (2400-640t)/640. But if they were to return to a it would fly 640t miles at 560mph which will take (640t/560) hrs
(2400-640t) / 640 = 640t / 560
560(2400 - 640t) = 640t x 640
t = 1.75hrs
<span>0.52%
First, let's convert that speed into m/s.
150 km/h * 1000 m/km / 3600 s/h = 41.667 m/s
Now let's see how much time gravity has to work on the ball. Divide the distance by the speed.
18 m / 41.667 m/s = 0.431996544 s
Now multiply that time by the gravitational acceleration to see what the vertical component to the ball's speed that gravity adds.
0.431996544 s * 9.8 m/s^2 = 4.233566131 m/s
Use the pythagorean theorem to get the new velocity of the ball.
sqrt(41.667^2 + 4.234^2) = 41.882 m/s
Finally, let's see what the difference is
(41.882 - 41.667)/41.667 = 0.005159959 = 0.5159959%
Rounding to 2 figures, gives 0.52%</span>