# What is the pressure force of the car on the bridge at a speed of v = 20m / s, when it is in the middle of the bridge

**What is the pressure force of the car on the bridge at a speed of v = 20m / s, when it is in the middle of the bridge, if the weight of the car is G = 35kn, and the radius of curvature of the bridge is r = 800m?**

Initial data: V (vehicle speed in the middle of the bridge) = 20 m / s; G (vehicle weight) = 35 kN; r (radius of curvature of the bridge) = 800 m.

Reference data: g (acceleration due to gravity) = 10 m / s2.

SI system: G = 35 kN = 35 * 10 ^ 3 m / s2.

1) Vehicle weight: m = G / g = 35 * 10 ^ 3/10 = 3500 kg.

2) Centripetal acceleration of the car in the middle of the bridge: an = V ^ 2 / r = 20 ^ 2/800 = 0.5 m / s2.

3) The pressure force of the car in the middle of the bridge: P = m * (g – an) = 3500 * (10 – 0.5) = 33 250 N or 33.25 kN.