A velocity time graph is shown in the adjoining figure.
Determine:
1) initial speed of car
2)maximum speed a attained by a car
3) part of the graph showing zero velocity
4) distance travelled by the car in first 6 seconds
Answers
Answer:
By studying the velocity-time graph given to us all the answers are determined as follows:
1) The initial speed of the car
From the graph we can see that the car starts its journey from the point of origin “O”, therefore,
The initial velocity of the car, u = 0 m/s
2) Maximum speed attained by a car
The final velocity or the maximum speed that the car is travelling with falls under the region AB i.e.,
The maximum speed = 20 m/s
3) Part of the graph showing zero velocity
In the figure, the car will have a velocity = 0 m/s on the line OEDC, which is on the time-axis of the graph.
4) Distance travelled by the car in first 6 seconds
In order to find the distance for the first 6 seconds, from the graph, we will calculate the sum of the area of the triangle and the area of the rectangle. Here, in the velocity time-graph the area corresponds to the distance travelled by car, therefore, it's unit will in “meters”.
So,
Area of the triangle OAE = ½ * base * height = ½ * 3s * 20 m/s = 30 m
And,
Area of rectangle ABDE = length * base = 20 m/s * (6-3) s = 20 * 3 = 60 m
∴ Distance travelled by car in first 6 secs = 30 + 60 = 90 m