Question

An airplane starts at rest and accelerates down the runway for 20 sec. at the end of the runway, its velocity is 80m/sec. What is its acceleration?

Answer 1

Answer:

The correct answer is - 4 m/s

Explanation:

Given:

time = 20 sec

velocity= 80 m/s

Accelaration = ?

Solution:

formula for the accelaration can be drive from the for

vi = vf + ( a.t)

0 m/s (rest) = 80 m/s + (a.20s.-1)

a.20.-1= -80,

we check if this is true;

0 m/s= 80 + -80 = 0 so its true.

so a.20.-1= -80,

a= 80/20 ,

Thus, the correct answers a = 4 m/s