A playground merry-go-round of radius 2.1 m has a moment of inertia 287 kg. m2 and is rotating at 10 rev/min about a frictionless vertical axle. Facing the axle, a 33 kg child hops onto the merry-go-round, and manages to sit down on the edge. What is the new angular speed of the merry-go-round? Answer in units of rev/min.

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?

The amount of potential energy possessed by an elevated object is equal to what?

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.