supposed to vacuum cleaner uses 120 J of electrical energy. If 45 J used to pull air into a vacuum cleaner, how efficient is the vacuum cleaner?

What type of wave requires a medium to transfer energy? Radio Mechanical Electromagnetic Light

2) Light reflects off of surfaces. It is also absorbed by opaque materials and transmitted through transparent objects. Consider this diagram of tvo sheets of construction paper.

Bill and Tom are both towing wagons. Bill's wagon weighs 10 pounds, and Tom's wagon weighs 20 pounds. Bill is pulling his wagon with twice the force that Tom is. How do the wagon speeds compare?

Each inner energy level of an atom has a maximum number of it can hold

In the military, night vision goggles are used to pull off secret missions into areas that are very dangerous. For this reason, the soldiers try to infiltrate at night so they can't be seen.

A scientist heats a piece of iron until it is glowing white-hot. he places the metal inside a metal box. he removes all of the air from the inside of the box.

Johanna is studying what happens to the energy as a ball rolls down a ramp. What is she studying? Check all that apply. 1. gravitational potential energy 2. electrical energy 3. kinetic energy 4. mechanical energy 5. elastic potential energy

The density of sugar is 1.59 g/cm3. the mass of a sample is 4.0 g. find the volume of the sample

How much force is needed to accelerate an object of mass 90 kg at a rate of 1.2 m/s2? 0.013 N 75 N 108 N 1080 N

No work is done on an object when a force acting on the object does not move it. True False