1. A 10.00 m ladder of weight WL = 355 N leans against a smooth vertical wall (meaning the wall only exerts a normal force perpendicular to the wall). A firefighter, whose weight is WF = 925 N stands 7.5 m up from the bottom of the ladder. The ladder makes a 50o angle with the ground. Find the forces that the ground and the wall exert on the ladder.
2. Two spheres are each rotating at an angular speed of 24 rad/s about axis that pass through their centers. Each sphere has a radius of 0.20 m and a mass of 1.5 kg. However, one is solid and the other is a thin-walled spherical shell. Suddenly, a net external torque due to friction (magnitude = 0.12 Nm) begins to act on each sphere and slows down the motion. How long does it take each sphere to stop completely?
3. A thermos contains 150 cm3 of coffee at 85.0oC. To cool the coffee, you drop in two 11 gram ice cubes into the thermos. The ice cubes are initially at 0oC and melt completely. What is the final temperature of the coffee? Treat the coffee as if it were water.
2. Two spheres are each rotating at an angular speed of 24 rad/s about axis that pass through their centers. Each sphere has a radius of 0.20 m and a mass of 1.5 kg. However, one is solid and the other is a thin-walled spherical shell. Suddenly, a net external torque due to friction (magnitude = 0.12 Nm) begins to act on each sphere and slows down the motion. How long does it take each sphere to stop completely?
3. A thermos contains 150 cm3 of coffee at 85.0oC. To cool the coffee, you drop in two 11 gram ice cubes into the thermos. The ice cubes are initially at 0oC and melt completely. What is the final temperature of the coffee? Treat the coffee as if it were water.