The figure given shows a velocity-time graph for a car starting from rest. The graph has three parts AB, BC, and CD. State how the distance travelled in any part is determined from the study of this graph.

When a velocity-time graph is made, the positive area under the velocity-time graph gives the distance travelled by an object. Therefore, to calculate the distance travelled in any part, we need to obtain the area of that part of the figure.

The figure given shows a velocity-time graph for a car starting from rest. The graph has three parts AB, BC, and CD Is the magnitude of acceleration higher or lower than that of retardation? Give a reason.

The slope of the velocity-time graph gives the acceleration of an object. From the given graph, we can see that the slope of AB is less than that of CD. Thus, we can say that retardation in CD is greater than acceleration in AB. Acceleration in part CD = 0 - v ο 2 . 5 t - 2 t = - v ο 0 . 5 t = - 2 v ο t (- ve sign depicts retardation). Acceleration in part AB = v ο - 0 t - 0 = v ο t . Therefore, the magnitude of retardation is twice the magnitude of acceleration.

E M B I B E

Together With Physics Class 9>Chapter 2 - Motion in One Dimension>PRACTICE QUESTIONS>Q 8

MEDIUM

9th ICSE

IMPORTANT

Earn 100

A body at rest is thrown downwards from the top of a tower. Draw a distance-time graph of its free fall under gravity during the first three seconds. Show your table to values starting from $t = 0$ with an interval of $1$ second ( $g = 10 m / s^{2}$ ).

Important Questions on Motion in One Dimension

MEDIUM

9th ICSE

IMPORTANT

Together With Physics Class 9>Chapter 2 - Motion in One Dimension>PRACTICE QUESTIONS>Q 9

The following table gives the displacement of a car with time. Draw the displacement-time and find the average velocity of the car. What will be the displacement of the car in $2.5 s$ and $4.5 s$ ?