A car of mass 1000 kg moves on a circular track of radius 40 m. If the coefficient of friction is 1.28. The maximum velocity with which the car can be moved, is

• 22.4 m/s

• 112 m/s

• $\frac{0.64 \times 40}{1000 \times 100}$m/s

• 1000 m/s

The escape velocity for the earth is 11.2 km/s. The mass of another planet 100  times mass of earth and its radius is 4 times radius of the earth. The escape velocity for the planet is

• 280 km/s

• 56.0 km/s

• 112 km/s

• 56 km/s

A body is thrown with a velocity of 9.8 m/s making an angle of 30° with the horizontal. It will hit the ground after a time

• 1.5 s

• 1 s

• 3 s

• 2 s

A gas expands 0.25 m³ at constant pressure 10³ N/m², the work done is

• 250 N

• 250 W

• 250 J

• 2.5 erg

A moving body of mass m and velocity 3 km/h collides with a rest body ofmass 2 m and stick to it. Now the combined mass starts to move. What will be the combined velocity?

• 4 km/h

• 1 km/h

• 2 km/h

• 3 km/h

Two rigid bodies A and B rotate with rotational kinetic energies E, and E, respectively. The moments of inertia of A and B about the axis of rotation are I_A and I_B respectively.

If ${\mathrm{I}}_{\mathrm{A}} = \frac{{\mathrm{I}}_{\mathrm{B}}}{2}$ and  E_A = 100 = E_B, the ratio of angular momentum (L_A ) of A to the angular  momentum ( L_B ) of B is

• 25

• 5/4

• 5

• 1/4

7.

The working principle of a ball point pen is

• Bernoulli's theorem

• surface tension

• gravity

• viscosity

Progressive waves are represented by the equation y₁ = a sin (ωt - x )  and y₂ = bcos (ωt - x ).  The phase difference wave is

• 0^o

• 45^o

• 90^o

• 180^o

Two boys are standing at the ends A and B of a ground, where AB= a. The boy at B starts running in a direction perpendicular to AB with velocity The boy at A starts running simultaneously with velocity v and catches the other boy in a time t, where t is

• $\frac{\mathrm{a}}{\sqrt{{\mathrm{v}}^2 + {\mathrm{v}}_1^2}}$

• $\sqrt{\frac{{\mathrm{a}}^2}{{\mathrm{v}}^2 - {\mathrm{v}}_1^2}}$

• $\frac{\mathrm{a}}{\left(\mathrm{v} - {\mathrm{v}}_1 \right) }$

• $\frac{\mathrm{a}}{\left(\mathrm{v} + {\mathrm{v}}_1\right)}$

A force F is given F = at + bt² where, t is time. What are the dimensions of a and b?

• [ M L T^-1 ] and [M L T^o ]

• [ M L T^-3 ] and [ M L² T^-4 ]

• [ M L T^-4 ] and [ M L T¹ ]

• [ M L T^-3 ] and [ M L T^-4 ]