Question 7A "lazy susan" is a disk-shaped rotating platform that a restaurant places at the center of a large dining table. Dishes of food are placed on the lazy susan and diners can rotate the lazy susan by hand to bring various dishes closer to them. A large torque exerted for a short time makes the motionless platform begin rotating rapidly, but that dangerous technique risks tipping over some of the food dishes. How can you make the same motionless platform and dishes begin rotating just as rapidly, but with a smaller, safer torque?1 pointDo the same angular impulse as the dangerous technique, but by exerting a smaller torque for a smaller time.Do the same angular impulse as the dangerous technique, but by exerting the smaller torque for a larger rotational mass.Do the same angular impulse as the dangerous technique, but by exerting the smaller torque for a smaller rotational mass.Do the same angular impulse as the dangerous technique, but by exerting a smaller torque for a longer time.

You are riding on a large carousel at an amusement park and you are enjoying the moving scenery as the carousel spins about its center of rotation. The ride comes to an end and the carousel gradually slows to a stop. Why does it take so long for the carousel to stop rotating?1 pointThe spinning carousel carries a large amount of angular momentum and the angular impulse needed to remove that angular momentum with a reasonable torque requires a long time.The spinning carousel has a large angular velocity and changing a large angular velocity requires a long time.The spinning carousel has a large rotational mass and changing a large rotational mass requires a long time.The spinning carousel has a large angular impulse and changing a large angular impulse requires a long time.

If two forces of equal magnitude act on an object that is hinged at a pivot, the force acting further from the pivot (irrespective of the force’s direction) always produces the greater torque about the pivot.Group of answer choicesTrueFalse

Question 5The chef at a pizza restaurant tosses a spinning disk of pizza dough into the air. As the disk stretches outward in midair and its diameter increases, what happens to the disk's angular momentum and angular velocity about the disk's center of mass? [Note that the disk's weight, which acts at the disk's center of gravity, produces zero torque on the disk about the disk's center of mass. Ignore any effects due to the air.]1 pointThe disk's angular velocity is constant, but the disk's angular momentum increases.The disk's angular momentum is constant, but the disk's angular velocity increases.The disk's angular momentum is constant, but the disk's angular velocity decreases.The disk's angular momentum and angular velocity are both constant.

A child stands on a horizontal rotating platform that is moving at constant angular speed. Thecentripetal force on the child is provided byA. the gravitational force on the child.B. the friction on the child’s feet.C. the tension in the child’s muscles.D. the normal reaction of the platform on the child.– 10 –2221 – 6510

Define pivot 2 marksThe point at which we apply the forceThe fixed point about which an object rotatesThe point around which the handle is locatedThe point at which we should fix the hinges