Explanation

1 kilometre (km) = 1000 metres (m)

So 0.05 km = 0.05 x 1000 m = 50 m.

Explanation

1 kg = 1000 g

So 4 kg = 4 x 1000 g = 4000 g.

Explanation

• 10^-9 second = Nano second (ns)
• 10^-6 second = Micro second (μs)
• 10^-3 second = Milli second (ms)
• 10^-2 second = Centi second (cs)
• 10^-1 second = Deci second (ds)

Explanation

The correct order goes from smallest to largest: 1 millimetre (mm) = 0.1 centimetre (cm), and 1 centimetre (cm) = 0.01 meter (m).

Explanation

• A unit is a standard quantity that is used to measure other quantities of the same kind.
• For example, the meter is a unit of length, the kilogram is a unit of mass, and the second is a unit of time.

Explanation

• Derived quantities are quantities that can be expressed in terms of fundamental quantities through multiplication, division, or raising to a power.
• Examples of derived quantities include area, volume, velocity, acceleration, force, and energy.
• These quantities are derived from the fundamental quantities and are not independent.

Explanation

• Physical quantities are attributes of the physical world, such as length, mass, time, temperature, and energy, that can be measured and quantified.
• Examples of physical quantities include the height of a building, the speed of a car, and the voltage of a battery.

Explanation

• Measurement involves comparing an unknown quantity (the measured) with a standard quantity (the unit) to determine its value.
• This process is a fundamental aspect of science and engineering, allowing us to quantify physical properties and phenomena.

Explanation

• When the rectangular piece of wood is kept in position A.
• Its entire weight is concentrated on a smaller area, resulting in maximum pressure on the table.

Explanation

• When we ascend or descend too quickly, our body struggles to adapt to the change in pressure, leading to altitude sickness or other injuries.
• This is why it's important to acclimate to higher elevations gradually, allowing our body to adjust to the decreasing pressure.