Which "sphere" does an astronomer most directly study?

a. biosphere

b. exosphere

c. geosphere

d. cryosphere E. atmosphere F. hydrosphere

F 600 J of work is done in 3 s, what is the power? (Power: P = W/t) 0.005 W 200 W 603 W 1800 W

you move a refrigerator 25 m this requires a force of 90 N how much work was done while moving the refrigerator

How does direct current differ from alternating current?

Two technicians are discussing oil filters. Technician A says that the oil will remain perfectly clean if just the oil filter is changed regularly. Technician B says that oil filters can filter particles smaller that the human eye can see.

The rate constant of a reaction is 7.8 * 10-3 s-1 at 25°C, and the activation energy is 33.6 kJ/mol. What is k at 75°C? Enter your answer in scientific notation.

What is the role of the air spaces in insulating materials? Select all that apply. They trap heat in the spaces. They puts gaps between the particles to slow down conduction. They dissipate energy faster.

Is it true or false that wave interference only occurs with transverse waves?

There have been several proposed atomic models during the last 150 years. Which model best illustrates the Bohr model. This model suggests that an atom's electrons orbit the nucleus in fixed patterns, much like the planets orbit the Sun.

During which type of change should you expect to see different chemical symbols before and after the change?

Ryan is examining the energy of the particles in a bar of gold. What is Ryan most likely studying? thermal energy electric energy potential energy internal energy