Which of these can be considered a system?

a computer

a car

a bicycle pedal

a pencil

a coffeemaker

A toy plane has a mass of 2.5 kg and is 18 m above the ground. It is moving at 4.5 m/s. How much mechanical energy does the toy plane have? 416 J 441 J 466 J 491 J

The energy that generates wind comes from what source? A Magnetic attraction B Solar radiation C Electromagnetic waves D Severe thunderstorms

The force of gravity on a person or object on the surface of a planet is called?

A block with a mass of 30 kg is located on a horizontal, frictionless tabletop. this block is connected by a rope to another block with a mass of 10 kg

It is acceptable for all types of waste to be either burned or buried in the same manner. true or false?

The maximum kinetic energy of photoelectrons is 3.10 ev. when the wavelength of the light is increased by 50%, the maximum energy decreases to 1.50 ev. part a what is the work function of the cathode?

Which of the following most completely describes an objects motion? A. a car travels 25 miles. B. The baby crawls 10 feet in 15 seconds toward the door. C. A marble rolls 10 m to the left D. The rain falls at a rate of one inch per hour

Why is the use of carbon-14 limited

Why do cell sometimes need to use active transport?

Why is carbon and nitrogen important?