Question

A helicopter weighs 3920 Newton's.calculatw the force on it if it is ascending up at a rate of 2m/s2. what will be the force on helicopter if it is moving up with the constant speed of 4m/s.​

Answer 1

Question:-

A helicopter weighs 3920 Newton's. calculate the force on it if it is ascending up at a rate of 2 m/s². what will be the force on helicopter if it is moving up with the constant speed of 4 m/s.

Given data:-

{ Mass = m; Force = F; Acceleration due to gravity = g (9.8 m/s²) ; Acceleration = a; }

—› F = 3920 N

—› a = 2 m/s²

—› Speed = 4 m/s

Case 1 :- Calculate the force on it if it is ascending up at a rate of 2 m/s²

Case 2 :- what will be the force on helicopter if it is moving up with the constant speed of 4 m/s.

Solution:-

{To find weight of helicopter}

we know helicopter move upword hence,

We take

{Acceleration due to gravity = Acceleration }

—› g = a ..... ( 1 )

Now, by formula of force,

—› F = m × a

—› F = m × g { from ( 1 )}

—› 3920 = m × 9.8 { from given }

—› m = 3920/9.8

—› m = 3920/9.8

—› m = 400 kg ..... ( 2 )

Now, for Case 1

—› F = m × a

—› F = 400 × 2 { from ( 2 ) & given }

—› F = 800 N

Now, for Case 2

Let, u be the intial velocity & v be the final velocity.

Let, assuse that speed as velocity

Now, before ascending upward initial velocity of helicopter is zero.

Hence, u = 0 m/s & v = 4 m/s

We know that helicopter move upward at distance 4 m in a sec.

Hence, Time ( t ) = 1 sec

now, to find acceleration

—› a = { v - u }/t

—› a = { 4 - 0 }/1

—› a = 4/1

—› a = 4 m/s² ...... ( 3 )

Now,

—› F = m × a

—› F = 400 × 4 { from ( 3 ) & given }

—› F = 1600 N

Hence, the 800 N force on it if it is ascending up at a rate of 2 m/s². & the 1600 N force on helicopter if it is moving up with the constant speed of 4 m/s.