A pulley system lifts a 500-lb. block 2.0 feet with an effort of only 50 lb. If the 50 lb. moves 30 feet, calculate the efficiency of the pulley system.

Juan lives 100m away from bill whats juan's average speed if he reaches bill home in 50 s

It takes 120 minutes for a man to ride his bicycle up the road to Alpe d'Huez in France. The vertical height of the climb is 1,120 m, and the combined mass of the rider and bicycle is 96 kg. What is the bicyclist's average power output, in W?

A projectile is launched at an angle above the ground. The horizontal component of the projectile's velocity, vx, is initially 40. meters per second. The vertical component of the projectile's velocity, vy, is initially 30. meters per second.

In a fission reaction of U-235 there was a release of 9.20x1011kJ of energy. What amount of mass in grams would have been lost? Recall that c = 3x108 m/s. Select one of the options below as your answer: A. 1.02 x 10-2 B. 1.02 x 101C. 1.02 x 109 D. 8.

Extensive deforestation was carried out on a piece of land to convert it into a farmland. what is the most significant cost involved in converting the land back into a forest? a. the soil quality must be improved using fertilizers. b.

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.

If you keep voltage constant and increase resistance resistance, what happens to current?

A scene in a movie has a stuntman falling through a floor onto a bed in the room below. The plan is to have the actor fall on his back, but a researcher has been hired to investigate the safety of this stunt.

During energy transformation, all energy systems: are a. 100 percent efficient b. lose energy c. gain heat energy d. create energy

An apple with a mass of 0.95 kilograms hangs from 3.0 meters above the ground. What is the potential energy of the apple