Explanation

• The heat from the Sun reaches Earth in the form of electromagnetic waves, which is called radiation.
• This includes ultraviolet (UV) rays, visible light, and infrared (IR) rays.
• Radiation is the transfer of energy through electromagnetic waves, without the need for a medium like air or water.

Explanation

The to and fro movement of a pendulum is called a vibration or oscillation.

It's a repeated back-and-forth motion about a central position.

Explanation

Explanation

When a sound wave strikes a surface and bounces back into the original medium, this is called reflection.

It’s the same principle behind echoes.

Explanation

Density = Mass / Volume

= 16 g / 160 cm³

= 0.1 g/cm³

Given the mass of 16 g and the volume of 160 cm³, the density of the piece of wood is 0.1 g/cm³.

Explanation

The diameter is the full distance across the circle through the center.

If the circle is labeled or measured and shows a span of 36 cm across, then the diameter = 36 cm is correct.

Explanation

The area of a square is given by the formula A = s², where A is the area and s is the length of a side.

Given A = 169 in², we can solve for s: s = √A = √169 = 13 inches.

Explanation

To find the percentage of spaces reserved, divide the number of shaded spaces by the total number of spaces and multiply by 100.

Number of shaded spaces = 8

Total number of spaces = 20

Percentage reserved = (8 / 20) * 100 = 40%

Explanation

Weight of 1 apple = 2 kg ÷ 4 = 0.5 kg

Weight of 10 apples = 0.5 kg × 10 = 5 kg

Explanation

Let's solve the expression 3(a ÷ b)^c with the given values: a = 36, b = 12, and c = 2.

First, calculate a ÷ b = 36 ÷ 12 = 3.

Then, raise it to the power of c: 3^2 = 9.

Finally, multiply by 3: 3 * 9 = 27.