Why is ground-level ozone a bigger problem during the summer than during the winter? question 4 options:

a.) there is less sunlight during the summer to produce ground-level ozone

b.) there is more sunlight during the summer to produce ground-level ozone

c.) ozone formation is not related to sunlight

acid rain is a

question 5 options:

a.) primary pollutant

b.) secondary pollutant

c.) great thing for the earth

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

On a day when the barometer reads 75.23 cm, a reaction vessel holds 250 ml of ideal gas at 20 celsius. an oil manometer ( ρ= 810 kg/m^3) reads the pressure in the vessel to be 41 cm of oil and below atmospheric pressure. what volume will the gas occupy under s. t.p.?

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?