Question

a car travels with 30 km/hrs for 30 minutes and then with a speed of 40 km/hr for 1 hour .find
1》the total distance travelled by the car
2》the total time of travel
3》the average speed of the car ​

Answer 1

Explanation:

Total distance = 30 × 0.5 + 40 ×1 = 55 km

Total travel time = 0.5 + 1 = 1.5 hours

Average speed = Distance/Time = 55 / 1.5 = 36.67km/hr

Hope this will help!!!

Answer 2

Given:

Car travels with 30 km/hr for 30 mins and then with 40 km/hr for 1 hour.

To find:

• Total distance travelled by car

• Total Time of travel

• Average speed of car

Calculation:

Distance is calculated by the product of speed and time. It is scalar quantity having only magnitude and direction.

Here , time has to be considered in hours unit.

Total distance be s :

$s = (30 \times \dfrac{1}{2}) + (40 \times 1)$

$= > s = 15 + 40$

$= > s = 55 \: km$

Total time of travel be t :

$\therefore \: \: t = \dfrac{1}{2} + 1 = \dfrac{3}{2} \: hr$

Average Speed is defined as the ratio of Total distance travelled to the total time taken to travel that specific magnitude of distance. It is also a scalar quantity because it involves another scalar quantity namely distance.

$\therefore \: v \: avg. = \dfrac{total \: distance}{total \: time}$

$= > v \: avg. = \dfrac{55}{ (\frac{3}{2}) }$

$= > v \: avg. = \dfrac{110}{3}$

$= > v \: avg. = 36.667 \: km {hr}^{ - 1}$