G"the force exerted on a bridge pier in a river" is to be tested in a 1: 10 scale model using water as the working fluid. in the prototype the depth of water is 2.0 m, the velocity of flow is 1.5 m/s and the width of the river is 20 m. of the hydrodynamic force on the model bridge pier is 5 n, what would it be on the prototype? (hint: pressure ratio is equal to the length-scale ratio) (5 points; ans: 5000 n)

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •