Explanation

• Ole Rømer was the first person to experimentally demonstrate that light has a finite speed in 1676.
• He used observations of Jupiter’s moon Io to estimate the speed of light.

Additional information:

• The modern accepted speed of light in vacuum is 299,792,458 m/s.

Last verified on 07-10-2026

Explanation

• Jupiter has the fastest rotation of all planets.
• It completing one rotation in about 9 hours 56 minutes.

Additional information:

• Venus has the slowest rotation.
• It taking about 243 Earth days.
• Earth: ~24 hours
• Mars: ~24 hours 37 minutes.

Last verified on 06-10-2026

Explanation

• The correct mathematical form is V = IR.
• Here V = voltage, I = current, R = resistance.
• Ohm’s law states that current is directly proportional to voltage when temperature is constant.
• It describes the relationship between voltage, current, and resistance.

Last verified on 12-04-2026

Explanation

• Mercury is closest to the sun.
• It is mostly made up of iron.
• It's surface covered with craters.
• It has no atmosphere and no moons.
• It's smallest planet.

Last verified on 06-10-2026

Explanation

• 1 Megawatt (MW) = 1,000,000 watts (W) = 10⁶ W.
• The watt (W) is the SI unit of power.

Additional information:

• 1 kilowatt (kW) = 10³ W
• 1 gigawatt (GW) = 10⁹ W
• 1 watt (W) = 1 W
• 1 milliwatt (mW) = 10⁻³ W

Last verified on 06-10-2026