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jehan4141
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A helicopter, starting from rest, accelerates straight up from the roof of a hospital. The lifting force does work in raising the helicopter. An 810-kg helicopter rises from rest to a speed of 7.0 m/s in a time of 3.5 s. During this time it climbs to a height of 8.2 m. What is the average power generated by the lifting force?
M = 810 kg
V0 = 0 m/s
Vf = 7 m/s
t = 3.5 s
y = 8.2 m
Force acting on helicopter: mg and FL (the lifting force)
It is accelerating upward. Find acceleration, a:
Vf = Vo + at
a = (Vf - Vo)/t
a = 2 m/s2
FL - mg = ma
FL = mg + ma
FL = 810(9.8+2)
FL = 9558 N
P = FL x avg V = 9558 N x 3.5 m/s
P = 33453 watts?
M = 810 kg
V0 = 0 m/s
Vf = 7 m/s
t = 3.5 s
y = 8.2 m
Force acting on helicopter: mg and FL (the lifting force)
It is accelerating upward. Find acceleration, a:
Vf = Vo + at
a = (Vf - Vo)/t
a = 2 m/s2
FL - mg = ma
FL = mg + ma
FL = 810(9.8+2)
FL = 9558 N
P = FL x avg V = 9558 N x 3.5 m/s
P = 33453 watts?
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