Estimating physical quantitiesAQA A-Level Physics: Mind map

Exam questions on Estimating physical quantities

1. A teacher asks a class to estimate the sizes and masses of familiar objects and particles to the nearest order of magnitude.
   A nucleus has a diameter of order 10⁻¹⁵ m and an atom has a diameter of order 10⁻¹⁰ m. Estimate how many times larger the volume of the atom is than the volume of its nucleus.2 marks
2. A student estimates the number of times a human heart beats in a lifetime. Assume a resting heart rate of about 70 beats per minute and a lifetime of about 80 years.
   Each heartbeat pumps about 70 cm³ of blood. Estimate the total volume of blood pumped in a lifetime, in m³, to the nearest order of magnitude.2 marks
3. A classroom is about 10 m long, 8 m wide and 3 m high. The density of air is about 1.2 kg m⁻³, the molar mass of air is about 0.029 kg mol⁻¹ and the Avogadro constant is 6.0×10²³ mol⁻¹.
   Estimate the mass of air in the classroom, to the nearest order of magnitude.3 marks