A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 7.0 m/s2. Secret agent Austin Powers jumps on just as the helicopter lifts off the ground. After the two men struggle for 11.0 s, Powers shuts off the engine and steps out of the helicopter. Assume that the helicopter is in free fall after its engine is shut off, and ignore the effects of air resistance. A. What is the maximum height above ground reached by the helicopter?
B. Powers deploys a jet pack strapped on his back 7.0s after leaving the helicopter, and then he has a constant downward acceleration with magnitude 1.0 m/s^2?
C. How far is Powers above the ground when the helicopter crashes into the ground?

a) 725.5 m

b) 630 m

Explanation:

Given data:

acceleration of Helicopter = 7.0 m/s^2

time spent upwards by helicopter = 11.0 seconds

a) Determine the maximum height above ground reached by the helicopter

h1  = at^2 /2

   = 7 * 11^2 / 2

   = ( 7 * 121 ) / 2 =  423.5 m  

  also v = a*t  = 7 * 11 = 77 m/s

also we calculate h2

h2 = v^2 / 2g

    = (77^2) / 2 * 9.81

    = 302 m

therefore the maximum height =  302 + 423.5 = 725.5 m

b) Given that ;  power deploys a jet pack strapped on his back at 7.0 s and with a downward acceleration of ; 1.0 m/s^2

Determine distance Power reaches before helicopter crashes

s = ut + 1/2 at^2

h.gt^2 - 77t - 423.5 m = 0

h.gt^2 - 77t = 423.5

t = 17. 66 secs

Yf = 423.5 + 77 *7 - 4.9 *7

Yf = 928.2

Vf = u + at

    = 77 - 9.8*7  = 8.4 m/secs

t' = 17.66 - 7 = 10.66 secs

hence

Yf = 725.5 - 8.4 * 10.66 + 1/2 * -1 * 10.66

   = 630 meters

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia