Suppose a vacuum cleaner uses 120 J of electrical energy is 45 J are used to pull air into the vacuum cleaner how efficient is the vacuum cleaner

Energy can be transferred from a closed system to the surroundings by: (A) Internal chemical reactions (B) Heat (C) Shaft work (D) Change in pressure without changing volume (E) Mass transfer

what is the best way to increase the rate of evaporation a. increase temperature b. decrease temperature c. decrease surface area

A bus and a car have an inelastic head-on collision. The bus has a mass of 1.5 * 10^3 kilograms and an initial velocity of + 20 meters/second. The car has a mass of 9.5 * 10^2 kilograms and an initial velocity of - 26 meters/second.

Which color of the visible light waves has the highest energy level?

In your own words, explain how energy is transported from the core to the surface of the sun by radiation and by convection.

A small rock remains at rest in outer space while an astronaut pushes horizontally on it with a force of 20 N. Which of the following must be true? A. There is another horizontal force acting on the rock. B.

If an igneous rock has very large crystals of minerals that you can see when looking at it, which type of igneous rock is it

You have a 60-foot roll of fencing and a large field. You want to make two paddocks by continuing the fencing down the middle of a rectangular enclosure. What are the dimensions of the largest such enclosure you can make?

Crystallization is a separation technique used to produce rock candy from a sugar solution. true or false

A car traveling in a straight line has a velocity of 3.79 m/s at some instant. After 5.4 s, its velocity is 11.9 m/s. What is its average acceleration in this time interval? Answer in units of m/s 2