I have a problem of a vehicle that impacts a barrier and knocks it over. At what minimum velocity does the barrier tip? (assuming it did not slide and there is no damage absorbing energy in the collision), sort like Barrier 2 ft wide, 2 ft tall, 6 ft long, 3600 lbs. Vehicle 2000 lbs, bumper height 1.5 ft. If we use energy KE of vehicle stopped by the impact = PE of barrier to move the CG up to the tipping point, 1/2 m v^2 = m g h so, v = sqrt (2 m g h / m) = sqrt (2 * 3600 * 32.2 * (sqrt 2 -1)/ 2000) = 7 fps the vehicle bumper height is not a factor and seems incorrect?