First slide

Rectilinear Motion

Question

A person travels along a straight road for the first half time with a velocity 10m/s and the second half time with a velocity 20m/s . Then the mean velocity is given by

Easy

A

30m/s
B

15m/s
C

10m/s
D

20m/s

Solution

Given that $t_{1} = \frac{t}{2}$
$\begin{array}{l} v_{1} = 10 m / s \\ t_{2} = \frac{t}{2} \\ v_{2} = 20 m / s \end{array}$
$∴$ The average velocity $= \frac{T o t a l d i s p l a c e m e n t}{T o t a l t i m e}$
$\begin{array}{l} = \frac{s_{1} + s_{2}}{t_{1} + t_{2}} \\ = \frac{v_{1} t_{1} + v_{2} t_{2}}{\frac{t}{2} + \frac{t}{2}} \\ = \frac{v_{1} + v_{2}}{2} \\ = \frac{10 + 20}{2} \\ = \frac{30}{2} = 15 m / s \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App