6. A car travels with speed 30 km/h for 30 minutes
and then with speed 40 km/h for one hour.
Find :
(a) the total distance travelled by the car
(b) the total time of travel
(c) the average speed of car
Answers
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
Explanation:
(a) Distance = Speed × Time
Equation Formed.;
(30×30)+(40×60)
900+2400
3500km ( In Minutes)