Question1
A space station is in the shape of a hollow ring, 450 in diameter. At how many revolutions per minute must it rotate in order to simulate Earth's gravity-that is, so that the normal force on an astronaut at the outer edge would be the astronaut's weight on Earth?
Question2
The driver of a 1800 car travelling on a horizontal road at 114 rapidly applies the brakes. Due to a slippery pavement, the friction of the road on the tires of the car, which is what slows down the car, is 26.0 of the weight of the car.
Question3
Matter in an accretion disk is in orbit around a black hole, but friction within the disk causes the matter to gradually spiral into the black hole. What will transform in terms of the observable properties of the black hole as this process continues.