1. When Tiger Woods drives a 46 g golf ball, he tries to hit it at a maximum height of 30 m. What is the initial speed of the ball when he hits it off the tee if, at the top of its path, it is traveling at 77.17 m/s? 2. A roller coaster with a mass of 1,400 kg is being pulled up a hill by a force of 20,000 N along a distance of 6om. What is the speed of the roller coaster after it has fallen back down to the bottom of the hill (h=0 at the bottom)?​

An electric current in a wire will push or pull on a permanent magnet. which statement best explains how an electric current creates an electromagnetic force on another magnet?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.