Answer:
The free end of the blade has a tangential velocity of about 88.19 m/s
Explanation:
The angular velocity of the blades is 
since the blades are 80 m long, then the tangential velocity of the free end of the blade is:

Explanation:
kinetic energy is energy that it possesses due to its motion.
Answer:
The electric field strength is 
Explanation:
Given that,
Magnetic field = 0.150 T
Speed 
We need to calculate the electric field strength
Using formula of velocity


Where, v = speed
B = magnetic field
Put the value into the formula



Hence, The electric field strength is 
A) 4.7 cm
The formula for the angular spread of the nth-maximum from the central bright fringe for a diffraction from two slits is

where
n is the order of the maximum
is the wavelength
is the distance between the slits
In this problem,
n = 5


So we find

And given the distance of the screen from the slits,

The distance of the 5th bright fringe from the central bright fringe will be given by

B) 8.1 cm
The formula to find the nth-minimum (dark fringe) in a diffraction pattern from double slit is a bit differente from the previous one:

To find the angle corresponding to the 8th dark fringe, we substitute n=8:

And the distance of the 8th dark fringe from the central bright fringe will be given by
