Answer:
a)30.14 rad/s2
b)43.5 rad/s
c)60633 J
d)42 kW
e)84 kW
Explanation:
If we treat the propeller is a slender rod, then its moments of inertia is

a. The angular acceleration is Torque divided by moments of inertia:

b. 5 revolution would be equals to
rad, or 31.4 rad. Since the engine just got started


c. Work done during the first 5 revolution would be torque times angular displacement:

d. The time it takes to spin the first 5 revolutions is

The average power output is work per unit time
or 42 kW
e.The instantaneous power at the instant of 5 rev would be Torque times angular speed at that time:
or 84 kW
I believe that is true.
hope this helps!
Answer: 
Explanation:
Given
Intensity must be reduced by a factor of 6
Intensity is given by 
Substitute
by 

So, the disk must be rotated by an angle of
.
Answer:
Electric Field intensity is zero.
The reason for that is:
All charges are placed at equal distances from the center of the square and have same magnitude and sign. This means they will exert equal and opposite forces on the test charge at the center. Net force will become Zero.