Physical Quantities

Which statement correctly describes what every physical quantity must consist of?

Why is stating a length simply as “5” physically meaningless?

A classroom measures 10 m by 5 m by 4 m. Taking the density of air as 1.2 kg m⁻³, calculate the mass of air it contains.

Which value is a reasonable estimate for the speed of sound in air?

Which value is a reasonable estimate for the wavelength of visible light?

Which value is a reasonable estimate for atmospheric pressure at sea level?

A student estimates that a bag containing 10 apples has a mass of about 10 kg. Using a reasonable estimate for the mass of a single apple, which statement is correct?

Which value is the density of water?

The period of a typical human heartbeat is approximately 1 s. Estimate the number of heartbeats in one hour.

A person walks at a steady pace for 10 minutes. Using a reasonable estimate for walking speed, estimate the distance travelled.

Which value is a reasonable estimate for the diameter of a human hair?

A student calculates a weight correctly as 9.81 but writes no unit in the final answer. According to Cambridge mark schemes, what is the most likely consequence?