Average Speed and Velocity - NEET Physics Questions
← Back to Kinematics

Average Speed and Velocity

Question 11:

A scooter is going towards east at 10 ms–¹ turns right through an angle of 90°. If the speed of the scooter remains unchanged in taking this turn, the change in the velocity of the scooter is :

1. 20.0 ms–¹ in south–western direction
2. zero
3. 10.0 ms–¹ in southern direction
4. 14.14 ms–¹ in south–western direction
View Answer

Change in a vector when it is rotated by an angle θ is

\[ \Delta V = 2V sin \left( \frac{\theta}{2} \right) \]

\[ \Delta V = 2\times 10 sin \left( \frac{90^{0}}{2} \right)= 20/\sqrt{2}= 10\sqrt{2}= 14.4 m/s \]

Question 12:

Figure shows position versus time graph of two rabbits running opposite to each other between two trees. Which of the following statements are true.

1. Rabbit A has greater magnitude of average velocity.
2. Rabbit B has greater magnitude of average velocity.
3. Both the Rabbits have same displacement.
4. Both the Rabbits have same constant speed.
View Answer

Distance is equal for both A and B. B is taking lesser time to complete so its speed is higher.

Question 13:

A car moves a distance of 200 m. It covers first half of the distance at speed 60 kmh–¹ and the second half at speed v. If the average speed is 40 kmh–¹, the value of v is

1. 30 kmh–¹
2. 13 kmh–¹
3. 20 kmh–¹
4. 40 kmh–¹
View Answer
Vav=30m/s