2 Instructional Objectives: Students will be able to:Define Projectile MotionDistinguish between the different types of projectile motionApply the concept to flying marble and measure its velocityTEKS 5.A and 5.B
3 Projectile Motion Two-dimensional motion of an object Vertical Horizontal
4 Types of Projectile Motion HorizontalMotion of a ball rolling freely along a level surfaceHorizontal velocity is ALWAYS constantVerticalMotion of a freely falling objectForce due to gravityVertical component of velocity changes with timeParabolicPath traced by an object accelerating only in the vertical direction while moving at constant horizontal velocity
5 Examples of Projectile Motion Launching a Cannon ball
8 (Acceleration due to gravity) EquationsX- ComponentY- ComponentVectorsNote: g = 9.8 m/s2(Acceleration due to gravity)
9 Factors Affecting Projectile Motion What two factors would affect projectile motion?Initial velocityAngleInitial VelocityAngle
10 Solving Problems Involving Projectile Motion Read the problem carefully, and choose the object(s) you are going to analyze.Draw a diagram.Choose an origin and a coordinate system.Decide on the time interval; this is the same in both directions, and includes only the time the object is moving with constant acceleration g.Examine the x and y motions separately.
11 Solving Problems Involving Projectile Motion 6. List known and unknown quantities. Remember that vx never changes, and that vy = 0 at the highest point.7. Plan how you will proceed. Use the appropriate equations; you may have to combine some of them.
12 Group Practice Interactive projectile motion calculator Other explanations and practice problems
13 Class ExerciseAn object is fired from the ground at 100 meters per second at an angle of 30 degrees with the horizontalCalculate the horizontal and vertical components of the initial velocityAfter 2.0 seconds, how far has the object traveled in the horizontal direction?How high is the object at this point?
17 Summary of ConceptsA projectile is any object upon which the only force is gravity,For our purposes we will not consideration air resistance, so we will take the approach all bodies fall at the same rate regardless of their massProjectiles travel with a parabolic trajectory due to the influence of gravity,There are no horizontal forces acting upon projectiles and thus no horizontal acceleration,The horizontal velocity of a projectile is constant (a never changing in value),There is a vertical acceleration caused by gravity; its value is 9.8 m/s/s, down,The vertical velocity of a projectile changes by 9.8 m/s each second,The horizontal motion of a projectile is independent of its vertical motion.
18 Independent Practice – problem sets Set 1 Set 2 Set 3
19 Labs CPO Manual B-1: Launch Angle vs. Range B-2: Launch Angle vs. SpeedB-3: Analysis of Range and Speed