Polly is pushing a box across the floor with a force of 30 N. The force of gravity is –8 N, and the normal force is 8 N. Which value could describe the force of friction if Polly could not move the box?]

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.