Explanation

To find the density of the steel balls, we need to use the formula for density:

Density = Mass/Volume

1. Calculate the total mass of the steel balls:

Each ball has a mass of 27 g, and there are 10 balls.

Total mass = 10 x 27 = 270 g

2. Calculate the volume displaced by the steel balls:

The initial volume of water is 20 cm^3

The final volume of water is 50 cm^3

The volume displaced by the steel balls is:

Volume displaced = 50 cm^3 - 20 cm^3 = 30 cm^3

3. Calculate the density of the steel:

Using the total mass and the volume displaced:

Density = 270 g / 30cm,^3 = 9.0 g/cm^3

Therefore, the density of the steel is 9.0 g/cm^3.

Explanation

Heat conduction is a process in which heat is transferred from the hotter part to the colder part in a body without involving any actual movement of the molecules of the body.

AGM 25-12-2022

Explanation

If A · B = 0, it means the vectors A and B are perpendicular.

The magnitude of the cross product is:

|A × B| = |A||B|sinθ

For perpendicular vectors, θ = 90°, so sin(90°) = 1

⇒ |A × B| = AB × 1 = AB

Explanation

The main source of energy in stars is nuclear fusion.

It is the process of combining atomic nuclei (usually hydrogen nuclei) to form a heavier nucleus, releasing vast amounts of energy in the process.

This energy is what makes stars shine.

Explanation

Ultrasound has several medical applications, including:

• Pre-natal scanning
• Diagnostic imaging
• Cancer treatment

In industry, ultrasound is used for:

• Cleaning and deburring
• Welding and bonding
• Non-destructive testing

Explanation

The rate of evaporation can be increased by:

• Decreasing atmospheric pressure
• Increasing temperature
• Decreasing humidity
• Increasing the surface area of the liquid

Explanation

The boiling point is the temperature at which a pure liquid changes state from liquid to gas at standard atmospheric pressure.

Key Points:

• The melting point is the temperature at which a solid changes state to a liquid.
• The freezing point is the temperature at which a liquid changes state to a solid.

Explanation

The work done on an object is calculated as the product of the force applied and the distance over which the force is applied:

Work = Force x Distance

= 6 N x 2 m

= 12 J

So, the work done is 12 Joule.

Explanation

A burning candle is an example of all three states of matter:

• Solid: The wax is in a solid state.
• Liquid: The melted wax is in a liquid state.
• Gas: The vaporized wax and combustion products are in a gaseous state.

Explanation

• Your weight, as measured on Earth, will be decreased if you move to a planet or moon with a weaker gravitational field.
• Weight is the force exerted on an object by gravity.
• It depends on both the mass of the object and the strength of the gravitational field.