PART - 2 CH - 13 Oscillations — Physics STD 11 Science — Question

Why does a child in a merry-go-round press the side of his seat radially outwards?

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

Choose the correct alternative :
(a) If the zero of potential energy is as infinity, the total energy of an orbiting satellite is negative of its kinetic/potential energy.
(b) The energy required to launch an orbiting satellite out of earth's gravitational influence is more/ less than the energy required to project a stationary object at the same height (as the satellite) out of earth's influence.

Human heart is an inbuilt clock. Comment.

When several passengers are standing in a moving bus, it is said to be dangerous. How will you justify this statement?

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

A particle is in linear simple harmonic motion between two points, A and B, 10cm apart. Take the direction from A to B as the positive direction and give the signs of velocity, acceleration and force on the particle when it is:
At the end B.

Calculate the volume of 1 mole of an ideal gas at STP.

Do all solids expand on heating? Name the solid that contracts on heating.