When the air inside a hot air balloon is heated, it expands and takes up a larger volume. as a result, it floats higher into the sky. what else happens to the air inside the balloon as it is heated? density decreases. density increases. mass decreases. mass increases.

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line