# Flat tire

Four rubber tires of outer radius 0.5 m, inner radius 0.1 m, and width 0.2 m are inflated with air to a gauge pressure of 200 kPa. The tires are then attached to a truck and the truck is placed on the ground at sea level. The bottom of the tires very quickly squish by 5 centimeters but the tires retain their shape otherwise. What is the total mass of the truck and tires in kg?

Details and assumptions

• The acceleration due to gravity is $$-9.8~m/s^2$$.
• The truck's weight is distributed equally on all four tires.
• Assume air is completely made up of $$O_2$$ and $$N_2$$. (Hint: This information is necessary for this problem.)
• Atmospheric pressure at sea level is 101.325 kPa.
• You may neglect any 'surface tension' of the tires.
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