DAY 56
Goals: SWBAT...
1. Recognize that the vertical and horizontal motions of a projectile are independent.
2. Relate the height, time in the air, and initial vertical velocity of a projectile using its vertical motion, and then determine the range using the horizontal motion.
3. Calculate distance traveled, flight time, and max height using a variety of given data
WARM-UP & HW Check
1. Equation Review: Copy the four kinematics equations from here into your equations chart
2. You accidentally throw your car keys horizontally at 8.0 m/s from a cliff 64-m high. How far from the base of the cliff should you look for the keys?
CLASSWORK
1. Review of Basic Projectile Motion Theory
Complete: pg 164 #35, 44
Whole class review
2. Review of Basic Projectile Motion Problem Solving
Complete problems 53 & 55 from pg 165
You have 7 min until I go over the solution for #53. Then you'll have 7 more minutes to try #55
before I post the solution for that problem.
MOVED TO HOMEWORK...
3. How Far Does it Go? Deriving the Range Equation
A. What does "range" mean?
B. Watch the video. Here's the notes. Write down any questions you have.
C. Copy the range equation into your equation chart (it's boxed at the bottom of the notes
page linked above).
D. Which variables (AKA, pieces of information) do you need to know to solve for the range?
t is the most common variable we need to initially solve for.
4. Using the Range Equation
Solve pg 165 #57
HW:
1. How Far Does it Go? Deriving the Range Equation
A. What does "range" mean?
B. Watch the video. Here's the notes. Write down any questions you have.
C. Copy the range equation into your equation chart (it's boxed at the bottom of the notes
page linked above).
D. Which variables (AKA, pieces of information) do you need to know to solve for the range?
t is the most common variable we need to initially solve for.
2. Using the Range Equation
Solve pg 165 #57
Solve pg 152 #10
Take some notes on the range equation, and practice solving a special problem alongside Mr. P
#Goals: SWBAT...
1. Find the CM of any object
2. Solve problems with with torques, forces, and inertia components
3. Describe the Coriolis Force
4. Via goals 1-3, prepare for our CH 8 Exam on Wednesday
WARM-UP & HW Check (problems 36 & 37 pg 215):
A. Find the Net Torque for the following scenario. Use the G. U. E. S. S. procedure to organize your solution. **Note: on the test, you will need to use GUESS on at least two problems - practice now...perfect later**
A 100cm ruler is initially oriented horizontally, with the fulcrum (AOR) at the 50cm mark. Mass One is located at the 20cm mark, and is 100g. Mass Two is at the 70cm mark, and is 200g. Assume the ruler is massless. What is the TNET of the system?
HINT: Be careful... when determining r1, how far is M1 from the AOR?
B. Using the same masses above, keeping Mass One at 20cm, and the fulcrum at 50cm, where on the ruler would you place Mass Two to put the system in equilibrium?
C. Give an example of an object that has both angular and linear displacement.
CLASSWORK:
1. Coriolis Effect
This is what causes storms to spin, but what is it???
Consider the following questions while watching the video. Our goal is to build the knowledge necessary to answer the last question.
1. From a fixed point of view, is the ball following a straight or curved path?
2. From a rotating point of view, is the ball following a straight or curved path?
3. So which is it? Is the ball following a straight path, or a curved path???
4. Consider the velocity components of the rotating system. How does the tangential velocity vary between the seat and the AOR?
5. Why does the ball appear to curve from the perspective of the rotating thrower/catcher? (Velocity is part of your answer...)
https://www.youtube.com/watch?v=dt_XJp77-mk
https://www.youtube.com/watch?v=i2mec3vgeaI
2. Practice Test Review (double points! 20-pt assignment)
Try the following from the chapter: 27, 33, 34
pg 222-227: 48, 50, 54, 57, 65 (a moment of inertia problem), 68, 75, 82, 87, 88, 91, 97,
Answers:
27: 5.5N
33: Sphere<solid disk<wheel. The less the moment of inertia, the less torque needed to give an object the same angular acceleration.
34: 5.99kg-m2
48: think about it.... ask me if you get stuck: j.alexander@birminghamcharter.com
50: Yes. Think about the explanation.... ask me if you get stuck: j.alexander@birminghamcharter.com
54: E<D<C<B<A
57: think about it.... ask me if you get stuck: j.alexander@birminghamcharter.com
65: The more mass there is far from the axis of rotation (AOR), the greater the moment of inertia. If the torque is fixed, the greater the moment of inertia, the less the angular acceleration. Therefore, the wheel with the mass mostly at the hub has the _________ moment of inertia, and the _______ angular acceleration.
68: think about it.... ask me if you get stuck: j.alexander@birminghamcharter.com
75: a: 197rad/s b: 492 rad
82: 3.8N-m
87: Fright = 63N Fleft = 37N
88: 1.16m
91: a: 21rad/s b; 16rev c: 1.0 x 102 rad
97: -1.3 x 10-3 m/s
Tutoring available after school Mon, Tues, and Wed until 4:30. Lunch almost every day.
HOMEWORK:
CH 8 Exam is coming!! Wednesday 3/2 :-)
- 1 page of notes
- practice test
- Make sure your equation sheet is organized