The velocity - time graph of the journey of two cars are given
1. Which car started first ?
2. How much time did each car take to attain the same velocity ?
3. Which car has lower acceleration ?
Answers
From the given graph we have to answer the following questions.
1. Which car started first?
Answer :
Car A because the line which represents the motion of the car appears to be inclined first than the line of the car B. The car starts at first second.
2. How much time did each car take to attain the same velocity?
Answer :
From the graph it is clear that both the cars attain the same velocity at the fifth second i.e., 40 m/s.
Since the car A started one second before the car B, so it would take one more second than the car B.
Car A takes 4 seconds.
Car B takes 3 seconds.
3. Which car has lower acceleration?
Answer :
We know,
In a Velocity time graph, the slope represents the acceleration while the area under the line or curve represents the Displacement.
But, we have to find the acceleration.
For Car A:
⇒ a = slope
⇒ a = dv / dt
⇒ a = 40 / 4
⇒ a = 10 m/s²
For Car B:
⇒ a = slope
⇒ a = dv / dt
⇒ a = 40 / 3
⇒ a = 13.33 m/s²
It is clear that the Car A will have lower acceleration.