Using aluminum wire(2.82x10^-8 ohm) of diameter 1.60mm, you want to wind a resistor that will dissipate 25.0 W when 25.0 V is applied across it . What length( in m) of wire is needed?

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.