A cyclist and his bicycle have a combined mass of 55kg. Total area of the tyres in contact with the road is 2.2 in contact with pressure exerted by the two on the ground.

force = 55*9.81 Newtons

pressure = force/area
if area is in meters^2
then force is in Pascals

To find the pressure exerted by the cyclist and the bicycle on the ground, you need to know the weight and the area of the contact patch.

First, let's convert the units to the metric system for consistency. The weight of the cyclist and the bicycle is given as their combined mass, which is 55 kg. Weight is the force exerted due to gravity, and it can be calculated by multiplying the mass by the acceleration due to gravity, which is approximately 9.8 m/s².

Weight = mass × gravity = 55 kg × 9.8 m/s² = 539 N (newtons)

Now, we need to find the pressure exerted by the contact patch. Pressure is defined as force per unit area.

Pressure = Force / Area

In this case, the force is the weight of the cyclist and the bicycle, which is 539 N. The area is given as 2.2 in². To convert this area to the metric system, we need to use the conversion factor 1 in² = 6.452 cm².

Area in cm² = 2.2 in² × 6.452 cm²/in² ≈ 14.194 cm²

Now, we can calculate the pressure:

Pressure = 539 N / 14.194 cm² = 37.99 N/cm² or 37.99 Pa (pascals)

Therefore, the pressure exerted by the cyclist and the bicycle on the ground is approximately 37.99 N/cm² or 37.99 Pa.