The velocity with which a projectile must be fired so that it escapes earth's gravitation does not depend on

• mass of the earth

• mass of the projectile

• radius of the projectile's orbit

• gravitational constant

The motion of planets in the solar system is an example of the conservation of

• mass

• linear momentum

• angular momentum

• energy

A body starting from rest moves along a straight line with a constant acceleration. The variation of speed (v) with distance ( s ) is represented by the graph

A lead shot of  1 mm diameter falls through a long column of glycerine. The variation of its velocity  'v'  with distance covered is represented by

Assertion: The earth is slowing down and as a result the moon is coming nearer to it.

Reason: The angular momentum of the earth moon system is not conserved.

• if both assertion and reason are true and the reason is the correct explanation of the assertion

• if both assertion and reason are true and the reason is not the correct explanation of the assertion

• if assertion is true but reason is false

• if both assertion and reason are false statements

Assertion:  The Coulomb force is dominating force in the universe. 

Reason: The Coulomb force is weaker than the gravitational force.

• if both assertion and reason are true and the reason is the correct explanation of the assertion

• if both assertion and reason are true and the reason is not the correct explanation of the assertion

• if assertion is true but reason is false

• if both assertion and reason are false statements

Assertion: The length of the day is slowly increasing. 

Reason: The dominant effect causing a slowdown in the rotation of the earth is the gravitational pull of other planets in the solar system.

• if both assertion and reason are true and the reason is the correct explanation of assertion

• if both assertion and reason are true and the reason is not the correct explanation of the assertion

• if assertion is true but reason is false

• if both assertion and reason are false statements

8.

A ball is thrown vertically upwards. Which of the following  plots represents the speed-time graph of the ball during its flight if the air resistance is not ignored?

• 

• 

• 

• 

An earthquake generates both transverse (S) and longitudinal (P) sound waves in the earth. The speed of S waves is about 4.5 km/s and that of P waves is about 8.0 km/s. A seismograph records P and S waves from an earthquake. The first P wave arrives 4.0 min before the first S wave. The epicentre of the earthquake is located at a distance about

• 25 km

• 250 km

• 2500 km

• 5000 km

Bernoulli's equation is a consequence of conservation of

• energy

• linear momentum

• angular momentum

• mass