Question

Tyre of a bicycle has volume 2000 cm³ . Initially, the tube is filled to 0.75 of its volume by air at atmospheric pressure of P₀ = 10⁵ Nm^–2. Area of contact of tyre with road is A = 24 cm² when total mass of bicycle and its rider is m = 120 kg. Calculate the number of strokes of pump, which delivers v = 500 cm³ volume of air in each stroke, required to inflate the type. 

Asume that area of contact of tyre with road remains unchanged. (g = 10 ms^–2) 

Answer 1

Atmospheric pressure, P₀ = 10⁵ Nm^–2 Increase in pressure (due to weight of bicycle and its rider)

Let temperature be T. 

Finally, number of moles of air in the tube 

Volume of these moles at atmospheric pressure, 

Initially, volume of air in tube (at atmospheric pressure) is V₀ = 0.75 × 2000 cm³.

= 1.5 × 10^–3 m³. 

 Volume (at atmospheric pressure) of air to be pumped in is 

 

Volume (at atmospheric pressure) of air pumped in each stroke is