WARM-UP (5min):
Constant Velocity
Open CH2 of the textbook to Page 38, and look at figure 2-12 in the bottom right corner of the page.
Show your work - don't write the questions
1. What is the position (m) of the runner at Time 0 (zero)?
2. What is the position (m) of the runner at Time 1 (1 sec)?
3. What is the difference in position (m) between those two times?
4. Calculate the velocity of the runner between T(0) and T(1).
5. Repeat steps 1-4 between T(2) and T(6). Find the velocity during that time period.
6. Read the classwork if you finish early
CLASSWORK:
1. A General Procedure for Problem Solving: "GUESSing" (15min)
Consider the following situation. Mr Alexander wants to fly from KVNY (Van Nuys Airport) to KTVL (South Lake Tahoe Airport) for his high school reunion. The reunion is at the airport, and starts at 5:00pm on Saturday. Mr. Alexander's Flight Plan (<-- click the link) shows the distance from Van Nuys to Tahoe. The Cessna 172 that Mr. Alexander rents averages a speed of 115 miles per hour on a clear day with no winds - today the winds are calm and are no factor. At what time should he leave if he wants to reach South Lake Tahoe in time for the reunion?
There is a process we can use when solving math problems like this one called GUESS. GUESS is an acronym that helps organize our problem solving. Here is what it stands for.
Givens: A given is any number written in the problem. Numbers include attached units.
Unknowns: An unknown is the number or numbers that the problem is asking us to calculate.
Equations: An equation is the algebraic representation of the relationship between the variables in the problem. Some problems may require multiple equations to solve.
Substitute: Once the equation has been identified, the givens are substituted in for the variables. Leave the unknown as a variable.
Solve: Use math to isolate all the non variables to one side of the equality and the unknown to the other side.
Let's apply this process to the problem of Mr Alexander's journey to South Lake Tahoe.
G Δx = 289.9 mi tf = 5:00 pm v = 115 mi/hr
U Δt
E
S
S
2. Practice
#006A: Practice the GUESS procedure on problems 49 & 51 from page 53 in chapter 2 of the textbook. (10min)
HOMEWORK: