Final answer:
A 60kg boy on a BMX bike could exert more pressure on a road than a 2500kg truck if the bike's tires have a smaller contact area with the ground. Pressure is determined by force per unit area, meaning lower force over a smaller area can result in higher pressure.
Step-by-step explanation:
It is indeed possible that a 60kg boy riding a BMX bike could exert more pressure on a road surface than a 2500kg truck. Pressure is defined as the force applied per unit area. If the bike's tires have a smaller contact area with the ground compared to the truck's tires, the bike could exert a higher pressure even though the total force (weight) is much lower for the bike.
For example, if the total force exerted by the truck on the ground is 2500 kg × 9.8 m/s² (gravity), but this force is distributed over a large area, the pressure will be lower. Conversely, the boy and his bike exert a force of 60 kg × 9.8 m/s², and if this force acts over a very small area, the resulting pressure may be higher than that of the truck.
To compare with a precise example: The truck's weight generates a force of approximately 24500 N, and if it has 4 large tires with a total contact area of 1.2 m², the pressure would be about 20417 Pa. If the boy and his bike have a total weight generating a force of 588 N, but the tires' contact area is just 0.01 m², the pressure would be 58800 Pa, which is indeed higher than the truck's pressure.
These are simplified scenarios and in real situations, factors like tire inflation pressure, road irregularities, and dynamical effects (like the distribution of mass) could influence the actual pressure exerted by the bike or truck.