### Solution to problems – class 9 – Set 1 Q 29

##### June 5, 2019

## Problem Statement

**A plane has a takeoff speed of 100 m/s and requires 1500 m to reach that speed. Determine the acceleration of the plane and the time required to reach this speed.**

## Solution

**It starts from rest. So initial velocity U = 0 **

Final velocity = take off velocity = V = 100 m/s ** To acquire that final velocity the distance travelled = S= 1500 m **

To find out the acceleration, we will use the equation **V ^{2} = U^{2} + 2 a S**

As U = 0, the equation becomes: V

As U = 0, the equation becomes: V

^{2}= 2 a S

Which gives acceleration

Which gives acceleration

**a = V**

^{2}/ (2 S)**= 100**

^{2}/ (2×1500) = 3.3 m/s^{2}**To find out the time required to reach that speed we will use this equation** **V=U + at **

**As U =0, the equation becomes V = at**

**which gives the time as: t = V/a = 100/3.3 = 30.3 sec**