A car travels with speed $30 k m h^{- 1}$ for $30$ minute and then with speed $40 k m h^{- 1}$ for one hour. Find :
(a) the total distance travelled by the car
(b) the total time of travel, and
(c) the average speed of car.

Open in App

Solution

Given, $Time travelled (t_{1}) = 0.5 h$
$Speed during 0.5 h (s_{1}) = 30 k m h^{- 1}$
$Time travelled (t_{2}) = 1.0 h$
$Speed during 1 h (s_{2}) = 30 k m h^{- 1}$
To find, Total distance travelled ( $d_{1}$ )
Total time taken ( $t$ )
Average speed

(a) $Total distance travelled (d) = Distance travelled in 30 m i n . (d_{1})) + Distance travelled in next 1 h o u r (d_{2})$
$d = (s_{1} \times t_{1}) + (s_{2} \times t_{2})$
$d = (30 k m h^{- 1} \times 0.5 h) + (40 k m h^{- 1} \times 1 h)$
$d = 15 k m + 40 k m$
$d = 55 k m$

(b) $Total time (t) = t_{1} + t_{2}$
$= 0.5 h + 1.0 h$
The total time of journey is $1.5 h$ .

(c) $Average speed = \frac{Total distance covered}{Total time taken}$
$= \frac{55 k m}{1.5 h r}$
The average speed during journey is $36.67 k m h^{- 1}$ .

Suggest Corrections

Similar questions

A car travels with speed of 30 km per hour for 30 minutes and then with speed of 40 km per hour for 1 hour:

a) find the total distance travelled by the car

b) find the total time of travel

Please explain me all this concept very clearly

60 k m h^{- 1}

40 k m h^{- 1}

30

30 k m h^{- 1}

40

40 k m h^{- 1}

210 k m

6 h o u r s

150 k i l o m e t r e s

50 k m h^{- 1}

60 k i l o m e t r e s

d

5 {kmh}^{- 1}

10 {kmh}^{- 1}

15 {kmh}^{- 1}

{kmh}^{- 1}

Join BYJU'S Learning Program