Before an ozone layer formed to reduce radiation, life existed

a. in the air.

c. in oceans and underground.

b. in trees and plants.

d. on land.

Which of the following represents the greatest risk factor for a stroke

The ratio of output power to input power, in percent, is called

The velocity of a ball changes from ‹ 8, - 4, 0 › m/s to ‹ 7.88, - 4.21, 0 › m/s in 0.03 s, due to the gravitational attraction of the Earth and to air resistance. The mass of the ball is 130 grams.

A board is hung from two springs, as shown in the figure above, with the board in equilibrium. Each spring has a spring constant of 10,000 N/m.

A greyhound at a racetrack can run at a speed of 16.0 m/s. What is the KE of a 20.0 kg greyhound as it crosses the finish line?

Chlorine is the atomic number 17 in the periodic table of elements. What information does the atomic number give you about the element chlorine? A) An atom of chlorine has 17 protons+. B) An atom if chlorine has 17 protons + and electrons-.

Which type of orbital will be occupied by the electrons of highest energy for the In + ground-state ion?

Consider a "crystal" consisting of two nuclei and two electrons. (a) Taking into account all the pairs of interactions, find the potential energy 1 of the system as a function of d.

jason hits a baseball off a tee toward right field. the ball has a horizontal velocity of 10 m/s and lands 5 meters from the tee. what is the height of the tee? show your work, including formula (s) and units.

What is the average amount of energy of motion in the particles of a substance