The car moves with a velocity of 2km/hr. in 5 minutes towards East, then moves again for 3km/hr. in 4 minutes. a. What is the car’s average acceleration? b. What is the car’s total displacement?
Answers
A car moves with a speed of 40km/h for 15 minutes and then with a speed of 60 km/h for the next 15 minutes. The total distance covered by the car is : 100km.
Given - Velocity and time
Find - Average accelaration and total displacement
Solution - The car's average acceleration is 7.1 km/h² and total displacement is 0.34 kilometres.
Average acceleration can be calculated by the formula - change in velocity/time.
Firstly converting time to hour-
1 minute = 1/60 hour
So, 5 minutes = 1/12 hour or 0.08 hour
and 4 minutes = 1/15 hour or 0.06 hour
Now, total time = 0.08 + 0.06
Total time = 0.14 hour
Average acceleration = (3-2)/0.14
Average acceleration = 7.1 km/h²
Since the car travelled in straight direction, the displacement will be total distance covered.
Total distance covered = 2*0.08 + 3*0.06
Total distance covered = 0.16 + 0.18
Total displacement = 0.34 kilometres
Thus, car's average acceleration is 7.1 km/h² and total displacement is 0.34 kilometres.