On computers, to express a number in scientific notation you use the letter “E” instead of the “x 10”. The “E” stands for “…times 10 to the…” . Therefore, the number 920,000 would be written as 9.2E5 which is the way a computer interprets 9.2 x 105.

(a) The average density of the earth is 5520 kg/m3. Express this in scientific notation. (Remember to use the E notation. Do not round. Do not write any zeros after the 2.)

kg/m3

(b) The average radius of the earth is 6.4 x 106 m. Expand this number by writing it without using scientific notation. Do not include commas.

(c) The average distance of the center of the earth from the center of the sun is 150,000,000 km. Write this number in scientific notation. Do not write any zeros after the 5.

km

To determine how fast Mercury rotates, we use radar. Suppose a radio wave traveling at the speed of light (3.00 108 m/s) travels from Earth to Mercury when they are9.17 1010 m apart.

(a) How many seconds does it take the radio wave to travel from Earth to Mercury?

s

(b) How many minutes is this?

min

(a) Earth’s radius is 6.4 106 m. Mars’ radius is 3.4 106 m. How many times larger is Earth’s radius than Mars’ radius? (Round to nearest integer.)

(b) Moon’s radius is 1.7 106 m. How many times larger is Earth’s radius than Moon‘s radius? (Round to nearest integer.)

(c) Earth’s diameter is 2 times its radius (or 1.28 107 m). Moon’s distance from Earth is 3.8 108 m. How many Earth diameters could be laid side by side between Earth and Moon? (Round to nearest integer.)

Express each of the fixed numbers in scientific notation:

a. 73,000 =

b. 0.00022 =

Express each quantity using a metric prefix:

a. 50,000 V =

b. 25,000,000 Ω = Ω

c. 0.036 A =

a. Convert 0.15 mA to μA

μA

b. Convert 4500 μV to mV

mV

c. Convert 47,000 pF to μF

μF

Express each of the following as a quantity having a metric prefix:

a. 31 x 10−3 A =

b. 5.5 x 103 V =

c. 20 x 10−12 F =

d. 3.3 x 106 Ω = Ω

Determine the following:

a. The number of microapers in 1 miliampere

b. The number of milivolts in 0.05 kilovolt

c. The number of megaohms in 0.02 kilohms

d. The number of kilowatts in 155 miliwatts

How many coulombs of charge do

50 × 1031

electrons possess?

×10

How many electrons does it take to make 80 μC of charge?

×10 electrons

Five hundred joules of energy are used to move an electric charge 100 C through a resistor. What is the voltage across the resistor?

V = V

Assume that a solar battery charger delivers 2.5 J of energy when 0.2 C of charge has been moved.

a.What is the voltage? V = V

b.If the solar cell has moved the charge in 10 s, what is the current?

I = A

How long does it take 20 C to flow past a point if the current is 10 A?

s

How many coulombs pass a point in 3 s when the current is 42 mA?

The picture bellow shows color-coded resistors. Determine the resistance value and the tolerance of each.

A. R = Ω Tolerance =

B. R = Ω Tolerance =

C. R = Ω Tolerance =

If you need a 270 Ω resistor with 5% tolerance, what color bands should you look for?

In the picture, what does each voltmeter indicate when the switch (SW) is in position 1? In position 2?

Position 1

V1 =

V2 =

Position 2

V1 =

V2 =

If 450 × 1015 electrons flow through a speaker wire in 150 ms, what is the current in amperes? The elctron electric charge is

1.6 × 10−19 C I = A