Answer to Question #203949 in Physics for Rethabile

Question

14. The movie Spiderman brought $114,000,000 in its opening weekend. Express this amount in gigadollars. (2)

A) 114 x 107 C) 0.114 E) 38 x 105

B) 11.4 D) 114,000

15. A mass of a newborn baby’s brain has been found to increase by about 1.6 mg + (4)

A) 0.007 g C) 8.91 g E) 2.3 g

B) 0.9818 g D) 14.0016 g

16. The speed of light in a vacuum is approximately 0.3 Gm/s. Express the speed of light in meters per second? (2)

A) 3 x 108 m/s C) 0.3 x 10-9 m/s E) 3 x 109 m/s

B) 0.3 x 10-8 m/s D) 0.3 m/s

17. An electronic advertising sign repeats a message every 7 seconds, day and night, a week. How many times did the message appear on the sign? (4)

A) 9 x 104

Answer 1

14. Prefix giga- means $10^9$. Thus, $\$114,000,000 = 0.114 \space gigadollars$. Answer is C.

15. $1.6 mg = 0.0016g$. Thus: $14g + 0.0016g = 14.0016g$. The answer is D.

16. $0.3Gm/s = 0.3\times 10^9m/s = 3\times 10^8m/s$. The answer is A.

17. There are the following amount of secons in a week: $7days\cdot 24hours\cdot60minutes\cdot 60sec = 604800sec$. If advertising sign repeats a message every 7 seconds, than it appeared:

$$N = \dfrac{604800}{7} = 86400\space times$$