Chipola College

Physical Science – Significant Figures, Units and Exponential Notation

1. Evaluate the following expressions using the proper significant figures:

(3.97x10^-4) /(2.939x10⁷)

answer: 1.35x10^-11

(9.61903x10^-3) X (4.00x10^-6)

answer: 3.85x10^-8

(6.009x10^-11)/(1.0002x10¹²)

answer: 6.007x10^-23

(5.5233x10⁴)/(0.0001320)

answer: 4.184x10⁸

(3.1474x10^-3) X (6.023x10²³)

answer: 1.895x10²¹

2. Express the following speeds in m/s using scientific notation. (Use 1 mi=1.609 km, 1 hour = 3600 s.)

70 mph

answer: 31.2 m/s

3.2x10³ mi/h

answer: 1.43x10³ m/s

100 km/h

answer: 27.8 m/s

3. A bird accelerates from rest to 5.00 km/hr in 2.3 seconds. What is its acceleration in m/s²? [Note unit change: 1 hr=3600 s, 1000 m =1 km. Also a=(v-v_o)t].

answer: 0.604 m/s²