(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Name the physical quantity which equals the rate of change of linear momentum.

State Newton's second law of motion. Is Newton's first law of motion contained in Newton's second law of motion?

What do you mean by an impulsive force?

State Newton's second law of motion.
A body of mass 400 g is resting on a frictionless table. Find the acceleration of the body when acted upon by a force of 0.02 N.

What do you mean by linear momentum of a body? A force causes an acceleration of 10 ms^-2 in a body of mass 1 kg. What acceleration will be caused by the same force in a body of mass 4 kg?

Use Newton's second law to explain the following:
We always prefer to land on sand instead of hard floor while taking a high jump.

Use Newton's second law to explain the following:
While catching a fast moving ball, we always pull our hands backwards.

A stone is dropped from a cliff 98 m high.
How long will it take to fall to the foot of the cliff?

A stone is dropped from a cliff 98 m high.
What will be its speed when it strikes the ground?

A stone is thrown vertically upward with a velocity of 9.8 m/s. When will it reach the ground?

A ball is thrown vertically downward with an initial velocity of 10 m/s. What is its speed 1 s later and 2 s later?

A ball is thrown upward and reaches a maximum height of 19.6 m. Find its initial speed?

A stone is dropped from a tower 98 m high. With what speed should a second stone be thrown 1 s later so that both hit the ground at the same time?

What do you mean by the conservation of momentum? Briefly, explain the c_ollision between two bodies and the conservation of momentum.

How does the pressure at a certain depth in sea water differ from that at the same depth in river water? Explain your answer.

What do you understand by atmospheric pressure?

Write the numerical value of the atmospheric pressure on the surface of earth in pascal.

What physical quantity is measured in torr? How is it related to the S.I. unit of the quantity?

Name the physical quantity which is expressed in the unit 'atm'. State its value in pascal.

We do not feel uneasy even under enormous pressure of the atmosphere above as well as around us. Give a reason.