Is it better to have lightbulbs in a parallel circuit or a series circuit

What is the momentum of a 2 kg object moving at 15 meters per second

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n

Astep up transformer has 250 turns on its primary and 500 turns on it secondary. when the primary is connected to a 200 v and the secondary is connected to a floodlight that draws 5a, what is the power output? show all of your work.