PART - 1 CH - 4 Laws of Motion — Physics STD 11 Science — Question

“All black surfaces are not good radiators.” Comment.

The sign of work done by a force on a body is important to understand. State carefully if the following quantities are positive or negative:
Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity.

Which of the solid, liquid and gas kept at the same mass and same temperature will have the maximum internal energy and which will have the minimum?

Name the type of motion associated with the molecules of a gas.

A small creature moves with constant speed in a vertical circle on a bright day. Does its shadow formed by the sun on a horizontal plane move in a simple harmonic motion?

A car travels at a speed of 60km/hr due north and the other at a speed of 60km/hr due east. Are the velocities equal? If no, which one is greater? If you find any of the questions irrelevant, explain.

The position of a particle moving in the X-Y plane at any time t is given by; x = (3t² - 6t) meters; y = (t² – 2t) meters. Select the correct statement:

1. Acceleration is zero at t = 0
2. Velocity is zero at t = 0
3. Velocity is zero at t = 1 second
4. Velocity and acceleration of the particle are never zero

Why does the time period of a swing not change when two persons sit on it instead of one?

Does the moment of inertia of a rigid body change with the speed of rotation?