Question

A plane has a takeoff speed of $88.3m/s$ and requires $1365m$ to reach that speed. Determine the time required to reach this speed.

• A. $20.8s$
  
• B. $30.s$
  
• C. $30.8s$
  
• D. $40.8s$
  

Answer 1

Answer: (C)

$30.8s$

Given, initial velocity is $u=0m/s$

Final velocity is $v=88.3m/s$ and traveled distance, $d=1365m$

Let $a$ be the acceleration of the plane.

Using $v^2-u^2=2ad$

$\therefore$ $(88.3{)}^2-0^2=2a(1365)$

$⟹$ $a=2.86m/s^2$

If $t$ be the required time.

Using $v=u+at$,

$88.3=0+2.86t$

$⟹$ $t=88.3/2.86=30.8s$