Projectile Motion

1. Define freefall. In freefall gravity is the only force acting on an object (air resistance is negligible)

2. Define projectile motion. (An object in freefall given a starting velocity.)

3. State the type of curve a projectile will follow when given constant velocity in one dimension and constant acceleration in another. (Parabola)

4. State the name of the path a projectile follows. (Trajectory)

5. State the acceleration in the x and y dimensions for projectile motion.
   • x-dimension accel = 0 always
   • y-dimension accel = 1g downward on Earth always
    
6. State the condition of velocity in both the x and y dimensions.
   • x-dimension velocity = constant always
   • y-dimension velocity = variable always
    
7. State the relationship of the velocity & acceleration vectors in the x direction to those in the y direction.
   • INDEPENDENT -- This makes it possible to treat

Formative Assessment: Physics Investigation

Follow up Questions

Projectiles Launched at an Angle

9. Solve bomber problems.
   • Why did the Japanese use a high level horizontal bomber in WWII to sink the USS Arizona?
   • Why would horizontal bombers not normally be used against ships in naval battles?

10. Solve artillery (baseball) problems.

11. State the relationship between the range for projectiles launched at complementary angles with the same initial velocity.

• Why would the Confederates use complementary angles to bombard Fort Sumter?

   

Homefun (formative/summative assessment): Read sections 4.2, do Practice Problems 5, 7, and 9 on page 125.

Circular Motion

1. Describe uniform circular motion. An object moves in a circular path at a constant speed.

2. Note that an object in circular orbit is in free fall.

3. Define tangential velocity. The instantaneous velocity of an object in circular motion. The direction is tangential to the circle.

4. Define centripetal acceleration.The acceleration due to the changing direction of an object in circular motion. Centripetal accelleration always points toward the center of the circle.

5. Define centripetal force. The force that causes an object to travel in a circular path. Centripetal force always points tward the center of the circle.

6. State the mathematical relationship between centripetatal acceleration (a), tangential velocity (v), radius of rotation (r).

   a = (v^2) / r

7. Name the force that keep a satelite in a circular orbit. Gravity

8. Name the force that acts as the centripetal force when a car rounds a semi-circular curve in a road. Friction, usually static friction.

9. Calculate centripetal force and centripetal acceleration.

 

Homefun (formative/summative assessment): problems 61, 65 page 166

Review of Objectives 1- 13 (1-3 days)

Formative Assessments:

1. Work review problems at the board

2. Work practice problems.

Metacognition Problem Solving Question: Can I still work the problems done in class, several hours or days later? Some amount of repetition on the exact same problems is necessary to lock in learning. It is often better to thoroughly understand a single example of a problem type than to work example after example understanding none of them completely.

Relevance: Good test preparation is essential to performance in physics class.

Homefun (formative/summative assessment): problems 33, 57, 59 pages 164-165; problems turn in on the day stapled to the back of the test.

Summative Assessment: Unit exam objectives 1-16