1- State how many significant figures are proper in the results of the following calculation:
(15.1)(0.20 – 30.05 + 170.2)
2- Cos 126.39°
3- Soccer fields vary in size. A large soccer field is 90.3 m long and 83.1 m wide. What is its smallest dimension in inches? (Assume that 1 meter equals 3.281 feet.)
4- Solve: (1.6 x 102) / (3.5 x 103)
5- Solve: (4 x 10-1)2
6- Sin 109.65°
7- Mount Everest, at 29,028 feet, is the tallest mountain on the Earth. What is its height in kilometers? (Assume that 1 kilometer equals 3,281 feet.)
8- What is the exponent of the solution to this expression?
4-2.1 x 45.8
9- What is the height in meters of a person who is 7 ft, 6.7 in. tall? (Assume that 1 meter equals 39.37 in.)
10- State how many significant figures are proper in the results of the following calculation:
(106.7)(98.2) / (46.210)(1.01)
11- Two legs of a triangle are 12.3 meters and 3.7 meters. The angle between them is 99.3 degrees. What is the length of the third side?
12- Tan 21.92°
13- Suppose that your bathroom scale reads your mass as 77.4 kg with a 0.5% uncertainty. What is the uncertainty in your mass (in kilograms)?
14- The speed of sound is measured to be 338.3 m/s on a certain day. What is this in km/h?
15- If the base of a certain ramp is 19.1 meters long, and its height is 4.9 meters, what is the angle in degrees of the incline?

Describe what is meant by “sound.” Explain how sound is created, transmitted, and sensed.
Doppler Effect Interface:
In the interface shown above the sound source (red box) is motionless. There are also two motionless observers (blue boxes). Assume the measurements in the interface are in meters. The tick marks between numbers are 0.2 meters each. It is common for sound waves to be shown with circles representing the wave front (the front of the compression part of the wave). Time is shown in the upper left hand corner next to the word tiempo.
Use the video above (or here) to calculate the frequency (how many waves pass a given point per 1 second) for this situation. Don’t forget your units!
Use the tick marks to measure the wavelength of the waves present. Remember that wavelength is the length of one full wave, so in this interface it is the distance between each wave front. Don’t forget your units!
Use your frequency and your wavelength from the above questions to calculate the velocity of your wave using the equation v = λ x f. Don’t forget your units!
The Doppler Effect in Sound
Now watch the video below (or here) of the interface again, but now the source (red box) is moving with a velocity of 0.50 m/s.
Examine the motion of the waves. Describe how the frequency changed on each side of the source.
What is the new wavelength on EACH side of the moving source? (You should have twoanswers here.) Don’t forget your units.
Remembering that the velocity of the wave HAS NOT changed (this means use the velocity you calculated above), use the equation v = λ x f and the wavelengths you measured above to calculate the new frequencies on EACH side of the moving source. Don’t forget your units.
Electromagnetic Waves and Light
Describe several ways that electromagnetic waves are similar to acoustical (sound) waves.
Describe several ways that electromagnetic waves and acoustical waves are different.
The Doppler Shift in Light
How is the Doppler shift used in astronomy?
What is meant by the terms red-shift and blue-shift?
Summary
Radar is the process of sending out an electromagnetic wave, having it reflect off of a body (such as an airplane or a water molecule), receiving the reflected wave, and then imaging the results. How do you think the Doppler shift can be used to measure wind speeds (Doppler radar)? (Hint: Think about how radio waves might reflect off of air particles that are moving at various speeds and in various directions.)
Explain why the pitch of an object approaching an observer (such as a fire truck with its siren on) differs from the pitch as it moves away from the observer. Remember that pitch is the brain’s interpretation of a sound’s frequency.
What is the Doppler effect, and why is it important to understand?

A design engineer submits a design to manufacturing for securing two (2) plates together for the purpose of sustaining a 2,000 pound force. The engineer claims that it will take three (3) steel 3/8-16 bolts to hold the plates together. If the design stress for sheer is 8,500 psi, is it a good idea to do this? How many bolts are required? If you chose to use rivets, how many of those would you need?
Why would you choose one type of fastener over another? Please show all calculations and list all assumptions