List the 7 main categories of electromagnetic energy ranked from lowest energy to highest. -astronomy question

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.

What was the purpose of the apollo program? to put a man in orbit to launch a spy satellite to launch a space station to put man on the moon