Question

a pilot decreases the landing speed from 70 m/s to 7m/s in 30seconds. What was the acceleration of the plane?

Answer 1

Given:-

→ Initial speed of the plane = 70m/s

→ Final speed of the train = 7m/s

→ Time taken = 30s

To find:-

→ Acceleration of the plane

Solution:-

In order to calculate the acceleration of the train, we have to use the 1st equation of motion :-

=> v = u + at

Where :-

• v is final speed of the body.

• u is initial speed of the body.

• a is acceleration of the body.

• t is time taken.

By substituting values in the above equation, we get :-

=> 7 = 70 + a(30)

=> 7 - 70 = 30a

=> -63 = 30a

=> a = -63/30

=> a = -2.1 m/s²

Thus, acceleration of the train was -2.1m/s² .

Some Extra Information:-

Acceleration:-

• Acceleration can be defined as the 'rate

of change of velocity'.

• It is a vector quantity.

• It's S.I. unit is m/s². Other units are

km/h² and cm/s².

Answer 2

Given :-

• A pilot decreases the landing speed from 70 m/s to 7 m/s in 30 seconds

To Find :-

• Acceleration of the plane

Solution :-

We have,

• Initial Velocity(u) = 70 m/s
• Final Velocity(v) = 7 m/s
• Time taken(t) = 30 s

We know that,

☆ a = (v - u)/t ☆

Where,

• a = Acceleration
• v = Final Velocity
• u = Initial Velocity
• t = Time taken

Substituting the given values we get,

$\implies$a = (7 - 70)/30

$\implies$a = (- 63)/30

$\implies$a = - 2.1 m/s^2

Hence, acclaration of the plane was - 2.1 m/s^2.