Question

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

Answer 1

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 ITS TRUE.

so a.20.-1= -80, a= 80/20 , Answers a= 4 m/s 

Answer 2

The acceleration of an airplane will be "4 m/s²".

According to the question,

The velocity is:

• $v_1 = 0$
• $v_2 = 80 \ m/s$

The time is:

• $t = 20 \ seconds$

As we know,

The formula of acceleration is:

→ $A = \frac{Change \ in \ velocity}{Time}$

or,

→ $A = \frac{v_2-v_1}{t}$

By substituting the values, we get

→     $= \frac{80-0}{20}$

→     $=\frac{80}{20}$

→     $= 4 \ m/s^2$

So the above answer is right.

Learn more about acceleration here:

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