1. Draw a picture labeling any numbers thta appear in the problem. (I don't always require this step but it can be very helpful.)
2. Identify the givens by looking for unit clues, key words and phrases like drop, rest, and "constat velocity."
3. List these givens with the variable, number, and units. Include the variable you are looking for in your list.
4. There are 4 kinematics equations. Find the formula that contains all of /only the variables and unknown.
5. Plug in numbers and units then solve.

"Race style" problems are where two bodies race side by side. In its most basic form, the two bodies cover the same distance in the same amount of time. Below is a video describing how to solve this type of problem and what we re looking for to give you credit to communicating your solution.

Highlights

• Each car has an acceleration and an intitial velocity.
• You will always make two lists of givens. One for each body. For organization and comunication reasons make the two lists side-by-side.
• The lists will always have a acceleration and an intial velocity.
• When solving, you will always use x = x_o + v_ot + (1/2)at²

Example #1

Question Hint Solution Video Solution Two runners are at track practice. Randal is tunning at a constant speed of 9.3 m/s. Race is ahead of Randal and running at 6.1 m/s. Randal is approaching Race to pass him. At the instant Randal is next to Race, Race begins to speed up at 0.77 m/s2. How much time is needed for Race to catch up to Randal? The question is talking about the runners starting side-by-side and ending up side-by-side. Therefore they cover the same distance in the same amount of time. There two accelerations so you will need two lists of givens. This HD video is on YouTube at http://youtu.be/S_Qtc7Hc_1I

Example #2

Question Solution Video Solution A police car stopped at a traffic signal. A red sports car passes him while accelerating at a constant 0.500 m/s2 and traveling at 8 m/s when he was 11.0 m away. The policeman takes a moment to think about what is happening and begins to accelerate at 3.50 m/s2. How much distance will it take to catch the red sports car? http://youtu.be/2J-kD6ExlEI

"Segmented" Problems (Multiple Accelerations)

These are problems with multiple accelerations for one moving body. The video below describes how these can be solved.       The main point to remember is that each acceleration gets it own list of givens. It the "race" style problem 2 cars with 2 accelerations get two lists of givens. In the segmented problems, again, multiple accelerations, for one body, also means multple lists of givens. One list for each acceleration. This concept will be built upon later in projectile motion.

Example of a "Segmented" Kinematics Problem Question Hint Solution Video Solution A car is traveling at 5.0 m/s when it speeds up at 3.0 m/s2 for 4.0 seconds. The car then travels at a constant velocity for 100.0 m. After which time it slows down with a deceleration of 2.00 m/s2 for 15 m. What is the car’s velocity at the end of the trip? A car is traveling at 5.0 m/s when it speeds up at 3.0 m/s2 for 4.0 seconds. The car then travels at a constant velocity for 100.0 m. After which time it slows down with a deceleration of 2.00 m/s2 for 15 m. What is the car’s velocity at the end of the trip? HINT: The vehicle undergoes multiple accelerations. Each acceleration gets its own list of givens. The final velocity for one segemnt becomes the initial velocity of the following segment. This YouTube video is located at http://youtu.be/TCIwwZi5qUU

Choose the best answer. It does not matter how many questions you miss. What matters is that you learn from any mistakes. Show all questions <=   => Two cars pull up to a start line at a dragstrip. Car A and car B. They are at rest. At the moment they are given the green light to race, a third car, car C, comes up along side of them traveling at a constant velocity of 22 m/s. If car A is acclerating at 6 m/s2 and car B is accelerating at 8 m/s2, then how many lists of givens would you need when organizing your work?   ?    1 list   ?    2 lists   ?    3 lists   ?    4 lists Two runners are jogging Runner A accelerating at 0.500 m/s2 and runner B is accelerating at 0.40 m/s2. At one point runners A and B are side by side. when this happens runner A's velocity is 3 m/s and B's velocity is 5 m/s. When solving this, what two variables are listed for each runner?   ?    x and vo   ?    vo and a   ?    t and vo   ?    x and a When solving a "race" style problem, which varables are the same value for each body?   ?    displacement and time   ?    final velocity and time   ?    displacement and final velocity   ?    displacement, time, and the final velocity Which eqaution is always used when solving race problems?   ?       ?       ?       ?     Two runners are jogging Runner A accelerating at 0.500 m/s2 and runner B is accelerating at 0.40 m/s2. At one point, runners A and B hear a starter's pistol and both decide to race each other. When the starter's pistol fires, runner B is 8 meters ahead of runner A. When they begin to race, runner A's velocity is 3 m/s and B's velocity is 5 m/s. When solving this, what should xo be for each runner?   ?     Runner A: vxo= 0 Runner B: xo= 0   ?     Runner A: xo= 8 m Runner B: xo= 0   ?     Runner A: xo= 0 Runner B: xo= 8 m   ?    Runner A: xo= 0 Runner B: xo= 3 m   ?    Runner A: xo= 3 m Runner B: xo= 5 m  OK