Under the action of a constant force, a particle is experiencing a constant acceleration. The power is

• zero

• positive constant

• negative constant

• increasing uniformly with time

A comet orbits around the Sun in an elliptical orbit. Which of the following quantities remains constant during the course of its motion ?

• Linear velocity

• Angular velocity

• Angular momentum

• Kinetic energy

Consider a satellite moving in a circular orbit around Earth. If K and V denote its kinetic energy and potential energy respectively, then (Choose the convention, where V = 0 as r → ∞)

• K = V

• K = 2V

• V = − 2K

• K = − 2V

Assuming the mass of Earth to be ten times the mass of Mars, its radius to be twice the radius of Mars and the acceleration due to gravity on the surface of Earth is 10 m/s². Then the acceleration due to gravity on the surface of Mars is given by

• 0.2 m/s²

• 0.4 m/s²

• 2 m/s²

• 4 m/s²

The semi-major axis of the orbit of Saturn is approximately nine times that of Earth. The time period of revolution of Saturn is approximately equal to

• 81 years

• 27 years

• 729 years

• $\sqrt[3]{81} \mathrm{years}$

16.

The x-t plot shown in the figure below describes the motion of the particle, along x-axis, between two positions A and B. The particle passes through two intermediate points P₁ and P₂ as shown in the figure

       

• The instantaneous velocity is positive as P₁ and negative at P₂.

• The instantaneous velocity is negative at both P₁ and P₂

• The instantaneous velocity is negative at P₁ and positive at P₂

• The instantaneous velocity is positive at both P₁ and P₂

A ball falls from a table top with initial horizontal speed V₀. In the absence of air resistance,which of the following statement is correct.

• The vertical component of the acceleration changes with time

• The horizontal component of the velocity does not change with time

• The horizontal component to the acceleration is non zero and finite

• The time taken by the ball to touch the ground depends on V₀

A man of mass 60 kg climbed down using an elevator.The elevator had an acceleration 4 ms^-2. If the acceleration due to gravity is 10 ms^-2, the man's apparent weight on his way down is

• 60 N

• 240 N

• 360 N

• 840 N

A uniform rod of length of 1 m arid mass of 2 kg is attached to a side support at O as shown in the figure. The rod is at equilibrium due to upward force T acting at P. Assume the acceleration due to gravity as 10 m/s² . The value of T is

• 0

• 2 N

• 5 N

• 10 N

CO⁻ ion moving with kinetic energy of 20 keV dissociates into O⁻ and C which move along the parent ion direction. Assuming no energy is released during dissociation, the kinetic energy of the daughters (K.E)_O and (K.E)_C are related as

• (K.E)_O⁻ = (K.E)_C

• (K.E)_O⁻ / (K.E)_C = 16/12

• (K.E)_O⁻ / (K.E)_C = 12/16

• (K.E)_O⁻ / (K.E)_C = 16/28