TEST PAPER LAWS OF MOTION

   Time:1 Hour       MM:-25

·         All questions are compulsory.

1.       Explain why some of the leaves may get detached from a tree if we vigorously shake its branch?     (2)

2.    What do you mean by acceleration due to gravity?   (2)

3.    You have a bag of cotton and an iron bar, each indicating a mass of 100 kg when measured on a weighing machine. In reality, one is heavier than other. Can you say which one is heavier and why?   (2)

4.    What is the nature of the distance−time graphs for uniform and non-uniform motion of an object?   (2)

5.       Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity?  (2)

6.    A stone of 1 kg is thrown with a velocity of 20 m s⁻¹ across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?(3)

7.    A bullet of mass 10 g travelling horizontally with a velocity of 150 m s⁻¹ strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of the force exerted by the wooden block on the bullet.   (3)

8.    Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 × 10²⁴ kg and of the Sun = 2 × 10³⁰ kg. The average distance between the two is 1.5 × 10¹¹ m.    (3)

9.    An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?  (3)

10.  Abdul, while driving to school, computes the average speed for his trip to be 20 km h⁻¹. On his return trip along the same route, there is less traffic and the average speed is 40 km h⁻¹. What is the average speed for Abdul’s trip?    (3)