A more ordinary example of conservation of momentum than a rocket ship occurs in a kitchen dishwashing machine. In this device, water at high pressure is forced out of small holes on the spray arms. Use conservation of momentum to explain why the arms rotate, directing water to all the dishes. 8 (a) If two automobiles collide, they usually do not stick together. Does this mean the collision is elastic? (b) Explain why a head-on collision is likely to be more dangerous than other types of collisions.

. As per our discussion of Torricelli's law, consider that a rock is dropped into a container before a hole is made at the y=0 level. When the hole is made, does the water emerge with a speed that is greater than, less than or equal to the speed without the rock? Explain your answer.

E 3. A spring is attached to the bottom of an empty swimming pool, with the axis of the spring oriented vertically. An 8.60- kg block of wood (density = 770 kg/m³) is fixed to the top of the spring and compresses it. Then the pool is filled with water, completely covering the block. The spring is now observed to be stretched twice as much as it had been compressed. Determine the percentage of the block's total volume that is hollow. Ignore any air in the hollow space. % 20 C $ 27 R 888 V % 5 T G tv MacBook Air 6: B P H & F7 N 8 M ( 9 AO K O P zoom CIA by m EA 04 M wies or the puffer delete 21 A A

A uniform disk of mass 10.0 kg and radius of 0.248 m spins at 302 rev/min on a low-friction axle. It must be brought to a stop in 1.00 min by a brake pad that makes contact with the disk at an average distance of 0.218 m from the axis. The coefficient of friction between the pad and the disk is 0.499. A piston in a cylinder of diameter 5.00 cm presses the brake pad against the disk. Find the pressure required for the brake fluid in the cylinder. Pa Need Help? Read It

The air around the spinning baseball shown in the figure (top view) experiences a faster speed on the left side than on the right side and hence a smaller pressure on the left than on the Left side Ay right. Suppose the ball is traveling in the x-direction at 34.6 m/s and it breaks Ay = 15.0 cm to the left, in the -y- Right side %3D direction. Assume the ball has a mass of 142 g and a radius Ax r = 3.55 cm. In addition, assume it travels at a constant speed v. = 34.6 m/s in the x-direction from the pitcher's mound to home plate, a distance Ax of 60.5 ft = 18.44 m. %3D Determine the pressure difference Ap, between the right and left sides of the ball. Apy : Pa

James wants to put up a wind tower. It is mounted on a 30m long, 800 kg rod, where it is supported by a piston at 4.5m away from the base and wind turbine is 1200kg. How much force is put on the piston supporting the system when James is working on it? See figure below.

Water is ejected from the water nozzle with a speed vo = 41.7 ft/sec. For what value of the angle will the water land closest to the wall after clearing the top? Neglect the effects of wall thickness and air resistance. What distance x to the right of point B does the water land? Answer: 0 = A X= 10 8 13.3' i i 45' Not to scale ft 6.9' B