Question

chapter 1 science skills
using scientific notation
light travels through space at a speed of 3.00×10^8 meters per second. how long does it take for light to travel from the sun to earth, which is a distance of 1.50×10^11 meters?

1. read and understand

what information are you given?
speed = 3.00×10^8 m/s
total distance = 1.50×10^11 m

1. plan and solve

what unknown are you trying to calculate?
time =?
what formula contains the given quantities and the unknown?
time = total distance / average speed
replace each variable with its known variable and known value.
time = (1.50×10^11 m) / (3.00×10^8 m/s)=(1.50 / 3.00)×(10^(11 - 8))(m/(m/s)) = 0.50×10^3 s = 5.00×10^2 s

1. look back and check

is your answer reasonable?
yes, the number calculated is the quotient of distance and speed, and the units (s) indicate time.
math practice
on a separate sheet of paper, solve the following problems.

1. the flow of water in a stream is 210,000 liters per hour. use scientific notation to calculate the amount of water that flows in a week (168 hours).
2. the density of a liquid is 8.03×10^(-1) kilogram per liter. what is the mass (in kg) of liquid in a full 100,000 liter tank?
3. how many balloons, each containing 6.02×10^23 particles of helium gas, can be filled from a tank that contains 1.204×10^25 helium particles?

12 physical science reading and study workbook · chapter 1

Explanation:

Step1: Solve problem 1

First, convert the flow - rate to scientific notation. $210000 = 2.1\times10^{5}$ liters per hour. Multiply by the number of hours in a week ($168 = 1.68\times10^{2}$ hours).

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Step2: Solve problem 2

Use the formula $\text{Mass}=\text{Density}\times\text{Volume}$. The density $
ho = 8.03\times 10^{-1}\text{ kg/L}$ and the volume $V = 100000=1\times 10^{5}\text{ L}$.

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Step3: Solve problem 3

Use the formula $\text{Number of balloons}=\frac{\text{Total number of particles}}{\text{Number of particles per balloon}}$. The total number of particles in the tank is $N_{total}=1.204\times 10^{25}$ and the number of particles per balloon is $N_{per - balloon}=6.02\times 10^{23}$.

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Answer:

1. $3.528\times 10^{7}$ liters
2. $8.03\times 10^{4}$ kg
3. 20 balloons