Explanation

• Kinetic energy is the energy of motion.
• It is the energy an object possesses when it is in motion, such as a rolling ball, a moving car, or a flying bird.
• The amount of kinetic energy an object has depends on its mass and velocity.

Explanation

• Fasteners (such as nuts and bolts) actually benefit from friction, as it helps keep them in place.

Disadvantages of friction:

• Energy loss: Friction converts useful energy into non-usable forms like heat.
• Wear and tear: Friction causes moving parts to wear out and deteriorate.
• Speed limit: Friction limits the maximum speed of automobiles.

Explanation

• The Earth takes approximately 23 hours, 56 minutes, and 4 seconds to complete one rotation on its axis, which is called a sidereal day.
• This is the time it takes for the Earth to rotate once relative to the fixed stars.
• The extra 4 minutes is due to the Earth's slightly ellipsoidal shape and the effects of the Moon's gravitational pull.

Explanation

• The Earth rotates constantly from West to East.
• Which is why the Sun appears to rise in the East and set in the West.
• This rotation is also the reason why we experience day and night in a 24-hour cycle.

Explanation

• Sounds travel faster through solids than through both gases and liquids.
• Solids have a more rigid structure, allowing sound waves to propagate more efficiently and at a faster speed.

Here's a comparison of sound speeds in different materials:

• Solids (e.g., steel): up to 5,960 m/s (13,140 ft/s)
• Liquids (e.g., water): up to 1,482 m/s (4,862 ft/s)
• Gases (e.g., air): approximately 343 m/s (1,125 ft/s)

Explanation

The formula for density is:

Density = Mass ÷ Volume

It represents how much mass is packed into a given volume.

Explanation

A Newton (N) is the unit of force in the International System of Units (SI).

Force (F) is equal to mass (m) times acceleration (a): F = ma.

"That gives a 1 kg body an acceleration of 1 m/s²".

Using F = ma, if m = 1 kg and a = 1 m/s², then F = 1 kg × 1 m/s² = 1 N.

Explanation

In a spinning dryer, the clothes are forced to move in a circle by the centripetal force provided by the drum.

However, the water in the clothes lacks this centripetal force (no direct contact with the drum),

So it moves in a straight line (due to inertia) and is flung outward through the holes in the drum.

Explanation

When an electron from a higher shell fills a vacancy in an inner shell, it emits a photon with a specific energy.

These are called characteristic X-rays because their energy depends on the atomic structure of the element.

Explanation

When two identical waves move in opposite directions, they give rise to stationary waves. 

Beats:

Beats occur when two waves with slightly different frequencies interfere, producing a fluctuating amplitude that can be heard as a pulsating sound. 

Constructive interference:

This happens when two waves with the same phase overlap, leading to an increased amplitude. 

Destructive interference:

This happens when two waves with opposite phases overlap, leading to a decreased or zero amplitude.