Question of Exercise 1

Question   Three particles A, B and C are thrown simultaneously with speeds and with A horizontally, B at an angle of 60° with the horizontal and C vertically in such a manner that they collide simultaneously at H, the highest point of the parabolic path of B. If the acceleration due to gravity is g, then the ratio of the speeds is

Option 1 1 : 1 : 1

Option 2 1 : 2 : 3

Option 3 3 : 1 : 1

Option 4 3 : 2 : 1

Maximum value of static friction is called

A: Limiting friction

B: Rolling friction

C: Normal reaction

D: Coefficient of friction

Solution:

Explanation:

Limiting friction is the maximum value of the static friction. When a body overcomes the limiting friction, the body starts moving.

Hence, option A is correct.

A running man has half the kinetic energy of that of a boy of half of his mass

The man speeds up by 1m/s , so that he has the same kinetic energy as that of the boy. The original speed of the man is?

Solution:

Two particles are projected simultaneously in the same

vertical plane, from the same point, both with different speeds and at different angles horizontally. The path followed by one, as seen by the other, is

A: a vertical line

B: a parabola

C: a hyperbola

D: a straight line making a constant angle ( ≠ 90 ^∘ ) with horizontal

Solution:

Explanation:-

which is a constant. So the path followed by one, as seen by the other, is a straight line, making a constant angle with the horizontal.

Hence, the correct option is (D).

Give two examples of the following Random motion

Solution:

Explanation:-

If an object in motion has no particular direction and its motion shifts unexpectedly, then it is said to have random motion.

The two examples of random motion are:

Motion of a football player.

Movement of a mosquito.

During an adiabatic process the pressure of a gas

is proportional to the cube of its adiabatic temperature.The value of  Cp/Cv for that gas is :

A:4/3

B:2

C:5/3

D:3/2

Solution:

Explanation:-