Physics Name Dale Per Newton's Laws & Circular Motion . Jessica is riding on a merry-go-round on an outer horse that sits at a distance of 8.0 m from the center of the ride. Petra is on an inner horse located 6.0 m from the ride's center. The merry-go-round turns around once every 40.0 s. i) Which girl is moving at greater linear speed? Explain why. (b) Calculate both girls' linear speeds. Petru: Jessica: 2. Friction as the centripetal for How large must the coefficient of friction be between the tires and the road if a car is to round a level curve of radius 85 m at a speed of 95 kmv/h? 3. Vertical normal as the centripetal force: A thrill seeker is riding through a vertical loop on a roller coaster. " Draw FBDs of the coaster at the top and the bottom of the vertical loop. Explain how the normal force on the passenger changes as hershe goes around the vertical circle. Where is the normal force a maximum and why? At what minimum speed must a roller coaster be traveling when upside down at the top of a circle if the passengers are not to fall out? Assume a radius of curvature of 8.6 m. 4 Horizontal normal as the centripetal force: In a "Rotor-ride" at a carnival, people pay money to be revolved in a vertical cylindrically walled "room." People describe this ride by saying they were being "pressed against the wall." Is this true? Is there really an outward force pressing them against the wall? If so, what is its source?" If not what is the proper description for their situation? If the room radius is 5.0 m, and the rotation frequency is 0.50 revolutions per second when the floor drops out, what is the minimum coefficient of static friction so that the people will not slip down? s. Critical speed: A popular trick of physics teachers is to swing a pail of water around in a vertical circle fast enough so that the water doesn't spill out when the pail is upside down. If'Mr. Sharkey's arm is D.60 m long, what is the minimum speed with which he can swing the pail so that the water doesn't spill out at the top of the path? & Apparent Weightlessness One of the counterweights in the elevator shaft has fallen off, so the elevator you're in descends much faster than planned, giving you that "floating stomach" feeling. If the elevator is descending at a rate of 3.0 m/s', how much would you appear to weigh? [assume your mass to be 65 kg) 7. Use an FBD to describe why it is impossible to revolve an object on a string in a perfectly horizontal circle
