posted by Freddy .
A 7900- helicopter accelerates upward at 0.90 while lifting a 1100- frame at a construction site.
A) What is the lift force exerted by the air on the helicopter rotors?
B)What is the tension in the cable (ignore its mass) that connects the frame to the helicopter?
C)What force does the cable exert on the helicopter
Your numbers require dimensions.
The forace exerted by the air
The problem does not state units, this assuming the weight is Kg and acceration is m/s2
g = 9.8
a = .9
from Netwon law
sum of force= ma
helicopter weight + frame weight X g + frame weight X a= force exerted by air
Force =(7900+1100) x 9.8 + (1100 x .9)
tension on the cabel
the forces acting on the cable is the frame
frame weight X g + frame weight X a= Tension in the cable
1100 x 9.8 + 1100 x .90=
why would the force of the air ONLY act on the frame? Isn't it also acting on the helicopter?