Instrument for measuring blueness of the sky or ocean is called ___________.

(A) Bathymeter

(B) Ceraunograph

(C) Cyanometer

(D) Barometer

Two students are asked to find the height of a particular building using a barometer. Instead of using the barometer as an altitude measuring device, they take it to the roof of the building and drop it off, timing its fall. One student reports a fall time of 2.0 s, and the other, 2.3 s. What % difference does the 0.3 s make for the estimates of the building’s height?