✓ Making sure your answer has the right units
✓ Using conversion factors correctly
✓ Checking that your answers make sense physically
1–3
1. Solve the equation
2. You are given that
3. Solve the equation
4–5
4. If
5. A pool is 2.0 meters deep. You dive in at an angle of 35 degrees to the surface of the water. If you continue in this direction, how far from the edge of the pool will you hit the bottom?
Illustration by Thomson Digital
6–10
6. A jet plane flies at about 10,000 meters. If 1 meter is 3.3 feet, how high does the plane fly in feet?
7. When you drive into Canada, the speed limit sign says 100 kilometers per hour. What is the speed limit in miles per hour? One mile consists of 1.6 kilometers.
8. You hire 5 painters to paint your house, which has a surface of 200 square meters. If each painter can paint 10 square meters per hour, how long does it take for them to paint the entire house?
9. Your dog eats a quarter pound of dog food each day. How often (in days) do you have to buy a 10-pound bag of dog food?
10. Your grandmother can knit a sweater in 3 days if she works 8 hours per day. She uses one bobbin of yarn every 2 hours, and each bobbin has 10 yards of yarn. How long is all the yarn in the sweater?
11–14
11. The speed of light is about 300,000,000 meters per second. Write this speed in scientific notation.
12. A femtosecond is 1 millionth of 1 billionth of a second. What is a femtosecond in scientific notation?
13. The radius of the sun is
14. Assume there are 7 billion people on Earth. If each person has a mass of 70 kilograms and the Earth has a mass of
15–16
15. A recipe calls for 500 milligrams of salt. You’re serving a large group, so you want to triple the portions of the recipe. How many grams of salt are required?
16. How many milliwatts are in 1 megawatt? Give the answer in scientific notation.
17–20
17. How many significant digits are in the number 303.4?
18. Calculate the sum
19. How many significant digits are in the number 5,003?
20. How many significant digits can you retain for
21–25
21. Calculate the sum 98.374 + 28.56 to the correct number of significant digits.
22. A physicist adds 0.25 gallons of paint to a container that already holds 10 gallons of paint. Given the significant digits of the quantities added, how much paint can she say is in the container?
23. Evaluate the equation
24. You measure the height of your apartment to be 2.6 meters high. If the apartment building has 8 floors, what is the height of the apartment building?
25. What is the result of
Chapter 2
Moving along with Kinematics
To describe motion, you can use terms like displacement, speed, velocity, and acceleration. Displacement is a distance in a particular direction. Speed is the distance traveled in a certain amount of time. If you combine speed with a direction, you get velocity. Acceleration measures how quickly velocity changes.
The Problems You’ll Work On
In this chapter you’ll move through the following topics:
✓ Finding the displacement in one and two dimensions
✓ Using velocity to determine the displacement
✓ Taking the average of the instantaneous speed
✓ Determining the change in velocity using acceleration
✓ Relating displacement, velocity, acceleration, and time
What to Watch Out For
You’ll speed through these questions if you keep the following in mind:
✓ Using the distance traveled, not the displacement, to determine average speed
✓ Remembering that velocity is the change in displacement in a certain amount of time
✓ Remembering that acceleration is the change in velocity in a certain amount of time
26–29
26. You leave your apartment and walk 2 blocks north, only to realize that you forgot your keys. You turn around and walk back 2 blocks south to get them. What is your total displacement?
27. A car is driven north for 5 miles, then south for 3 miles, and then north again for 2 miles. What is its displacement?
28. A pair of figure skaters skates together