Class 9 (Science assignment)

 

A. Scientific Reasoning Questions

Answer each question with a suitable scientific reason.

1.     Why does a passenger move backward when a bus suddenly starts moving?

2.     Why does a goalkeeper move his hands backward while catching a fast-moving football?

3.     Why does a person experience a backward push when jumping forward from a boat?

4.     Why is it more difficult to push a loaded trolley than an empty trolley?

5.     Why does a stone fall toward the Earth when it is released from a height?

6.     When a person jumps from a stationary boat onto the bank, the boat moves backward. Why does the boat move in the opposite direction?

B. Numerical Questions

1.     A bicycle starts from rest and accelerates at 2 m/s² for 5 seconds. Calculate its final velocity.

2.     A force of 30 N acts on a body of mass 6 kg. Calculate the acceleration produced in the body.

3.     A car is travelling at 10 m/s and accelerates uniformly at 2 m/s² for 5 seconds. Find its final velocity.

4.     A body moving with a velocity of 20 m/s comes to rest in 4 seconds. Calculate its acceleration.

5.     A force of 40 N is applied to a body of mass 8 kg. If the body starts from rest, calculate its velocity after 5 seconds.

6.     A ball of mass 2 kg is moving with a velocity of 6 m/s. Calculate its momentum.