First slide

Average Velocity

Question

A car covers $\frac{1}{3}$ part of total distance with a speed of 20km hr^-1 and second $\frac{1}{3}$ part with a speed of 30 km hr^-1and the last $\frac{1}{3}$ part with a speed of 60 km hr^-1. The average speed of the car is

Moderate

A

$55 {kmhr}^{- 1}$
B

$30 {kmhr}^{- 1}$
C

$45 {kmhr}^{- 1}$
D

$37.3 {kmhr}^{- 1}$

Solution

$t_{1} = \frac{\frac{x}{3}}{20} = \frac{x}{60}; t_{2} = \frac{\frac{s}{3}}{30} = \frac{s}{90}$
$t_{3} = \frac{\frac{s}{3}}{60} = \frac{s}{180}$
$v_{av} = \frac{s}{t_{1} + t_{2} + t_{3}} = \frac{s}{\frac{s}{60} + \frac{s}{90} + \frac{s}{180}} = 30 km / h$

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