Explanation

Sound waves are mechanical vibrations that can disturb air particles around a candle flame.

This disturbance causes the flame to flicker due to pressure variations in the air.

Explanation

Friction always acts opposite to the direction of motion, resisting movement.

Since work = force × displacement × cos θ, and θ = 180°, cos 180° = –1, so work is negative.

Explanation

Explanation

Ingenuity is a robotic helicopter that operates on Mars as part of NASA's Perseverance rover mission.

It is a small, autonomous helicopter that uses rotors to lift off the Martian surface and explore the planet from the air.

Ingenuity made history by becoming the first aircraft to fly on another planet in April 2021.

Explanation

Dentists use concave mirrors to illuminate inaccessible places in the tooth.

The concave shape of the mirror allows it to reflect light and images from small, hard-to-reach areas.

Such as the back of the mouth or between teeth.

Explanation

When a wave passes from one medium to another, its frequency remains unchanged.

However, its speed, wavelength, and direction may change.

Explanation

Mass is not a characteristic of a wave.

The characteristics of a wave include:

• Amplitude (the maximum displacement of the wave from its equilibrium position)
• Period (the time taken by the wave to complete one oscillation)
• Velocity (the speed at which the wave travels)
• Wavelength (the distance between two consecutive points on the wave that are in phase)
• Frequency (the number of oscillations per unit time)

Explanation

Very high frequency is the ITU designation for the range of radio frequency electromagnetic waves from 30 to 300 megahertz,

with corresponding wavelengths of ten to one meter.

ND17-7-2023

Explanation

Perhaps the most familiar example of resonance in everyday life is swinging on a playground swing.

The first push or pump sets the swing in motion.

Each subsequent push or pump is delivered at just the right time to increase the amplitude of swing.

Explanation

 According to Gauss's Law, the net electric flux through a closed surface depends on the net charge enclosed.

If equal and opposite charges are present inside the surface, their total is zero, so the net electric flux is also zero.