1.) An amusement park ride is called The Rotor (In CA "The Gravitron"). It consists of a fast-rotating cylinder with a "drop-away" floor. Riders stick to the walls as the floor falls away, held in place by friction and centripetal force. If the coefficient of static friction is 0.800 and the radius of the cylinder is 5.00 m, find the minimum tangential speed necessary to keep the riders safely stuck on the wall. a. Draw a picture. b. Draw a free-body diagram. c. Find the minimum safe speed the rotor must turn.

Macmillan Learning Your computer has an optical disk drive that can spin up to 10,000 rpm (which is about 1045 rad/s). If a certain disk is spun at 352.9 rad/s during the time it is being read, and then comes to rest over 0.569 seconds, what is the magnitude of the average angular acceleration of the disk? average angular acceleration: If the disk is 0.12 m in diameter, what is the magnitude of the linear acceleration of a point 1/3 of the way out from the center of the disk? linear acceleration: x10 rad/s² TOOLS m/s²

An ultracentrifuge accelerates from rest to 100,000 rpm in 2.30 min. (a) What is its angular acceleration in rad/s2?      _________rad/s2 (b) What is the tangential acceleration of a point 10.7 cm from the axis of rotation?_________m/s2 (c) What is the radial acceleration of this point at full rpm?_________m/s2 (d) Express this radial acceleration as a multiple of g._________g

Intro Physics I, Homework #7 See Walker Ch. 5, 6.1, 6.3, 7.1-7.2, 13.1 Submit to Google Classroom by 10 P.M., Monday, April 4 Remember to show all work and include units In Newton's late 17th century era, there were relatively accurate estimates, from terrestrial and astronomical observations and experiments, of the distance of the Earth to the Sun (dEs = 150 million 1. kilometers) and the circumference of the Earth (Cp = 40,000 kilometers [the meter was later defined during the late 18th century French revolution in relation to the size of the Earth]). Newton further estimated, likely based on the density of rocks, that the Earth was a solid sphere with a density about 6 times the density of water, which has density of pwater = 1 g/cm³.

Problem 4 An amusement park ride consists of a large vertical cylinder that spins about its axis fast enough that any person inside is held up against the wall even when the floor is removed. The coefficient of static friction between the person and the wall is us = 0.3 and the radius of the drum is R = 2m. (a) Find wmin, the minimum angular speed at which the drum should rotate such that the person is held up even if the floor is removed. (hint: when the floor is removed, the person is held up by the static frictional force). (b) Find the linear speed of the person when the drum is rotating at the minimum angular speed you found in (a) (cC) Suppose that the drum started from rest and reached the speed you found in (a) in 120 seconds. During this time the drum had constant angular acceleration. Find the number of rotations made by the person within this time.

18. A car traveling on a flat (unbanked) circular track accelerates uniformly from rest with a tangential acceleration of 1.70-m/s. The car makes it one fourth of the way around the circle before it skids off the track. Determine the coefficient of static friction between the car and the track. Hint: you need to find the total acceleration of the car. Answer: 0.572

During a very quick stop, a car decelerates at 7.69m/s?. a) What is the angular acceleration of its 0.195-m-radius tires, assuming they do not slip on the pavement? rad/s? b) How many revolutions do the tires make before coming to rest, given their initial angular velocity is 89 rad/s? rev c) How long does the car take to stop completely? d) What distance does the car travel in this time? e) What was the car's initial velocity? m/s