Explanation: The Doppler effect, applicable to both sound and electromagnetic waves, describes the change in frequency due to motion. Approaching a stationary sound source at high speed raises the perceived pitch, while receding lowers it. This shift in observed frequency, caused by the relative motion between the source and the observer, is the Doppler effect.

Explanation: The formula determines the number of images, and if the result isn't a whole number, it's rounded to the nearest integer. This approach ensures practical application, simplifying interpretation and usage where precise whole numbers are typically more relevant and useful.

Explanation: Joule (J) is a unit of energy, not specifically pressure energy. Pressure energy, stored in a fluid due to force per unit area, is calculated as Pressure × volume. Its dimensional formula, M L² T⁻², signifies mass, length squared, and time squared, representing its units in the SI system.

Explanation: The orbital velocity of a satellite around a planet decreases with increasing radius of its orbit. This velocity is influenced by the mass of the central body (planet) and the distance from it (radius of orbit), adhering to the principles of gravitational attraction and centripetal force in orbital mechanics.

Explanation: Buoyancy is determined by two factors: 1. The volume of the object submerged in the fluid—more submerged volume increases buoyant force. 2. The density of the fluid—the denser the fluid, the greater the buoyant force exerted on the object, influencing its ability to float or sink.

Explanation: Free fall of an object near Earth's surface is an example of uniform acceleration. Acceleration due to gravity causes the object to fall downward. This acceleration remains constant at approximately 9.8 m/s², causing the object's velocity to increase uniformly as it descends due to gravitational attraction.