A bicycle tire pump has a piston with area 0.47 in2. Do not include any parentheses around the letters or symbols.)Ī. If any of the combinations yield the same force, give them the same ranking. A force F1 is exerted on piston 1. Rank the resultant force F2 on piston 2 that results from the combinations of F1, A1, and A2given from greatest to smallest. The cross-sectional areas of piston 1 and piston 2 are A1 and A2, respectively. The piston chambers and the connecting tube are filled with an incompressible fluid. Pistons are fitted to two cylindrical chambers connected through a horizontal tube to form a hydraulic system. What is the minimum speed that a thrown ball would need to just reach the ceiling? Ans. The ceiling of an arena is 50 m above the floor. (a) What is their kinetic energy? _ J (b) If the rider coasts up the hill without pedaling, how high above its starting level will the bicycle be when it finally rolls to a stop? _ mġ0. A bicycle and rider going 15 m/s approach a hill. Ignoring air resistance, how fast are the divers going when they hit the water? Ans. The cliff divers at Acapulco, Mexico, jump off a cliff 28.7 m above the ocean. How high (in m) will the swing be at the high point?Ĩ. A child on a swing has a speed of 5.2 m/s at the low point of the arc (see the figure below). What is its speed when it hits the ground? Ans. A student drops a water balloon out of a dorm window 14 m above the ground. If air resistance is negligible, how fast (in m/s) is the tool going just before it hits the ground?ħ. A worker at the top of a 597-m-tall television transmitting tower accidentally drops a heavy tool.

What force had to act on that end? _ lbĦ. (a) How much work is done? _ft-lb (b) The other end of the lever is pushed down 3 ft while lifting the rock. In the figure, the rock weighs 105 lb and is lifted 1 ft by the lever. If a 140 N force is required to keep the car moving, how much work (in J) does the driver do?ĥ. The driver pushes the 1,220 kg car to the gas station. A motorist runs out of gas on a level road 240 m from a gas station.

How fast must the tackle be going before the collision for their speed afterward to be zero?Ĥ. A running back with a mass of 70 kg and a speed of 7 m/s collides with, and is held by, a 105-kg defensive tackle going in the opposite direction. What was the original speed of the clay (in m/s)?ģ. The clay sticks to the wood on impact, and their joint velocity afterward is 2.9 m/s. A pitcher throws a 0.80 kg ball of clay at a 3.0 kg block of wood. The change in momentum is the car’s momentum when traveling 21 m/s minus its momentum when going 0 m/s. Using the alternate form of Newton’s second law, compute the force (in N) needed to accelerate a 1,290 kg car from 0 to 21 m/s in 15 s.

Water whiz ma