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.