ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements.

Question

An object is dropped from a platform 400 ft high. Ignoring wind resistance, what will its speed be when it reaches the ground?

12,800 ft/s
7800 ft/s
160 ft/s
89 ft/s

Answer 1

the platform height is one significant figure

all of the responses are at least two significant figures

Answer 2

V^2 = Vo^2+2g*h = 0+64*400 = 25,600
V =