Lift force exerted by the air on the rotors=143244 N
Explanation:
we use Newtons second law
F- (M+m)g=(M+m)a
F= lift force
m= mass of helicopter= 13000 Kg
M= mass of car= 2000 lb=907.2 kg
a= acceleration= 0.5 m/s²
g= acceleration due to gravity
F- (M+m)g=(M+m)a
F=(M+m)(a+g)
F=(13000+907.2)(0.5+9.8)
F=143244 N
Answer: An electric motor
Explanation:
I took the quiz for physics and this was the answer
Answer:
44.1 m
Explanation:
<u>Given:</u>
= speed of sound in air = 343 m/s
= speed of sound in the rod = 
= times interval between the hearing the sound twice = 0.12 s
<u>Assumptions:</u>
= length of the rod
= time taken by the sound to travel through the rod
= time taken by the sound to travel to through air to the same point = 
We know that the distance traveled by the sound in a particular medium is equal to the product of the speed of sound in that medium and the time taken.
For traveling sound through the rod, we have
..........eqn(1)
For traveling sound through the air to the women ear for traveling the same distance, we have

Hence, the length of the rod is 44.1 m.