ncert solutions physics class 11th

An example of the periodic motion is Earth's revolution. In this, the motion repeats itself after regular intervals of time. In oscillatory motion, the object moves back and forth about a mean position like a vibrating spring or pendulum. It is a type of periodic motion. Although, oscillatory motions are periodic, however, not vice versa. Oscillatory motion typically follows sinusoidal patterns and involves a restoring force.

The key characteristics of SHM include:

• The amplitude remains constant in ideal SHM.
• The motion is periodic and follows a sine or cosine function.
• The acceleration is proportional and opposite to displacement.
• The time period and frequency are independent of amplitude.
• In SHM, the energy oscillates between potential and kinetic forms, with total energy remaining constant. SHM is a fundamental concept in physics that helps in analyzing wave-based and mechanical systems.

In Simple Harmonic Motion (SHM), the restoring force is directly proportional to the displacement from the mean position. It is a periodic motion and acts in the opposite direction. SHM follows the equation, F=? kx, where k is the force constant and x is the displacement. Simple Harmonic Motion is characterized by constant frequency, sinusoidal oscillations, and energy interchange between potential and kinetic forms. Examples are the vibrating springs,  the motion of a pendulum (for small angles), and molecules in a lattice.

According the Chapter 10 Thermal Properties of Matter, there are three primary methods of heat transfer - radiation, convection, and conduction. Convention takes place in fluids, conduction in solids, and radiation does not require a medium and involves the emission of electromagnetic waves. Each method plays a role in engineering applications like heating systems, insulation, and solar devices, and in natural phenomena. These methods operate under different physical principles.

Calorimetry is used to measure the amount of heat exchanged in the chemical or physical process. It is used to determine the heat transferred from or to a substance. It is useful in determining latent heat, specific heat, and energy changes in reactions. The principle is based on the law of conservation of energy, stating that in an isolated system, the hotter object's heat lost is exactly equal to the cooler one's heat gained, provided there is no exchange of heat with surroundings. 

The amount of heat needed to increase the temperature of one kilogram of a substance by one degree Celsius (or one Kelvin) is the specific heat capacity. It is measured in J/kg·K and it is a material-specific property. Substance with high specific heat makes them useful in thermal regulation systems such as water takes longer to heat or cool.
The formula is Q=mc? T, where m is mass, c is specific heat, and? T is the temperature change.

Conservative forces (like gravity or spring force) conserve mechanical energy and do not depend on the path taken. The work done by the conservative forces is recoverable.
Non-conservative forces (like friction or air resistance) dissipate energy as heat or sound. It depends on the path. When non-conservative forces act, mechanical energy is not conserved.

Energy is measured in joules (J). It is the capacity to do work while power is the rate of using energy or doing work. Power is measured in watts (W). One watt equals one joule per second. Power talks about how fast the work is done, and energy is about how much work is possible. 

When without slipping a body rotates and translates simultaneously is called rolling motion, such as a wheel on a road. It is the combination of rotatory and translatory motion. The point of contact has zero velocity relative to the surface in pure rolling. It is a condition in which there is no slipping or sliding during rolling.