A child is on a spinning merry-go-round and the child walks to center of it. Is angular momentum preserved if only the child is the system? Is angular momentum preserved if the system is the child and the merry-go-round?

What type of electromagnetic wave is used in security pens? a. x-rays c. microwaves b. visible light d. ultraviolet radiation select the best answer from the choices provided

Which statement correctly describes the current in a circuit that is made up of any two resistors connected in parallel with a battery? a. the current in the battery and in each resistor is the same b. the current the battery equals to the sum of the currents in the resistors c.the current in the battery is less than the current in either resistor d. the current in the battery equals to the product of the currents in the resistors

How to tell if two objects are in thermal equilibrium 1.the objects have the same temperature 2.the objects are the same size 3.the objects are touching each other 4.the objects temperatures are changing