Amodel of a helicopter rotor has four blades, each of length 3.80 m from the central shaft to the blade tip. the model is rotated in a wind tunnel at a rotational speed of 450 rev/min. a. what is the linear speed of the blade tip? b. what is the radial acceleration of the blade tip expressed as a multiple of the acceleration of gravity?

a)V= 179.056 m/s

b)

Explanation:

Given that

Length of blade = 3.8 m

Rotational speed N= 450 rev/min

We know that

  ω=47.12 rad/s

Linear velocity

We know that linear velocity V =  ω x r

Here r = 3.8 m

So by putting the values

V =  ω x r

V = 47.12  x 3.8 m/s

V= 179.056 m/s

Radial acceleration  

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j