A person who weighs 691 N is riding a 89-N mountain bike. Suppose the entire weight of the rider plus bike is supported equally by the two tires. If the gauge pressure in each tire is 8.40 x 105 Pa, what is the area of contact between each tire and the ground?

Answer 1

F=691+89=780 N
p=(F/2)/A=F/2A =>
A=F/2p=780/2•8.4•10⁵=4.6 10⁻⁴m²