Question

a car travels with speed 30 km/h for 30 min and then with speed 40 km/h for 1 h. find: a)total distance travelled by the car b)the total time of travel,and c) the average speed of car

Answer 1

In 30 min the car travelled 15km. And the last 1 hour it travelled 40 km. so it totally travelled (40+15=55) 55km

Answer 2

Answer:

The total distance is 55 km, the total time is 1.5 hours and the average speed is 36.67 km/h

Explanation:

Step 1 : Write down the relevant formulas :

Distance = Speed × Time

Average speed = Total distance / Total time.

Step 2 : Solve the questions.

1) Total distance = Distance traveled at 30 km/h in 30 minutes + Distance traveled for 1 hr at 40 km/h

Distance traveled at 30 km/h = 30 × 0.5 = 15 km

Distance traveled at 40 km/h = 40 × 1 = 40 km

Total distance = 40 km + 15 km = 55 km

2) Total time = time taken in the first part of the journey + time taken in the second part of the journey

= 0.5 + 1 = 1.5 hours

3) Average speed = Total distance / Total time.

This is given by :

= 55/1.5 = 36.67 km/h