Question

A plane is traveling at 95 m/s as it sets down the landing gear on the runway. It travels 250 m before coming to rest. What is the plane's deceleration?

Answer 1

We know that- v² = u² + 2as---------------------- A

; where v is the final velocity

u is the initial velocity

a is the acceleration of the body

s is the distance travelled

Now, u = 95 m/s

v = 0 m/s [ as the plane is coming to rest finally]

s = 250 m

Therefore, from A, we can say that-----

0² = 95² + 2 * a * 250

Or, a = (-)95²/(2 * 250) m.s^-2

= - 9025/500 m.s^-2

= - 18.05 m.s^-2

Here the negetive sign in the value of the acceleration tells us that it is actually negetive acceleration( that is, the plane is slowing down), or deceleration, and the value of the deceleration is 18.05 m.s^-2.