Asmall 0.280-kg object moves on a frictionless horizontal table in a circular path of radius 4.10 m. the angular speed is 3.08 rad/s. the object is attached to a string of negligible mass that passes through a small hole in the table at the center of the circle. someone under the table begins to pull the string downward to make the circle smaller. if the string will tolerate a tension of no more than 128 n, what is the radius of the smallest possible circle on which the object can move?

Which situation will have the highest resistance? a. long wire and high temperatureb. short wire and high temperaturec. long wire and cold temperaturedshort wire and low temperature

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

What is the role of lenses in microscopy?