[Answers: 29.6 s and 2500 lbf in tension] What effects? The pressure is P = 120 kPa and the pipe diameter is D = 8 cm. Assume the density of water is 1000 kg/m^3. Problem 5-6: Find the force in the coupling between the cars when the train is slowing down. (a) Find the time required for the train to stop after the brakes are applied, and (b) Find the force in car B when 4300 lbf is applied but the brakes on car A are not applied. The train weighs 18 tons and car B weighs 13 tons. A constant braking force of 4300 lbf is applied to car A. A light train made of two cars travels at 45 mi/h. Car A is in the front. Problem 5-7 (Adapted from Dynamics by Beer & Johnson, 6th edition): Determine if it would have been "OK" to neglect the pressure magnitude and direction of the total force (not force in the x-direction) of the flange bolts on the pipe bend. Neglecting the weight of the pipe bend and the water in the bend, determine the force in the coupling between the cars. The pipe diameter is 25 cm and the water velocity is Vi = 2.2 m/s. At the outlet of the bend, the pressure is Pi = 350 kPa, the pipe diameter is Di = 25 cm, and the water velocity is Vo = 2.2 m/s. At the inlet to the bend, the pressure is Pi = 350 kPa, the pipe diameter is Di = 25 cm, and the water velocity is Vi = 2.2 m/s. The bend is connected to the two pipes by flanges. The flanges are held together by flange bolts.