Projectile An object that is launched by a force and continues to move by its own inertia. The only force acting on it is gravity. (in free fall) http://www.physicsclassroom.com/class/vectors/Lesson-2/What-is-a-Projectile

Trajectory The path that a projectile traces.

4 Types of Projectile Motion Dropped (straight down, (a = g) Trajectory is straight line down vy = gt http://www.physicsclassroom.com/class/1DKin/Lesson-5/Acceleration-of-Gravity

4 Types of Projectile Motion Dropped (straight down, a = g) 10.00 3.80 1.80 0.00 -9.8 m/s2 http://mmsphyschem.com/putTo.htm

Dropped vs Thrown Straight Down Dropped Thrown time time velocity velocity slope = g (both) and vf = vi + gt

4 Types of Projectile Motion 2. Launched straight up (then falls down, a = g) Trajectory is a straight line up & down video -9.8 m/s2 -9.8 m/s2 -9.8 m/s2 http://www.vias.org/physics/bk1_05_03.html

4 Types of Projectile Motion 2. Launched straight up 3.80 1.80 0.00 -9.8 m/s2

4 Types of Projectile Motion 3. Launched horizontally (a = g) Trajectory is half a parabola https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj2gq7-mLXPAhUF4SYKHS1_BKwQjRwIBw&url=http%3A%2F%2Fwww.physicsclassroom.com%2Fclass%2Fvectors%2FLesson-2%2FHorizontally-Launched-Projectiles-Problem-Solving&psig=AFQjCNELCE2OC_vCsuYCUpZUg7PfH7-UJQ&ust=1475259683571516

4 Types of Projectile Motion 3. Launched horizontally, cont Horizontal Velocity 3.80 1.80 0.00 Vertical Velocity -9.8 m/s2

4 Types of Projectile Motion 3. Launched horizontally, cont. Independence of horizontal and vertical motion Only when they act in concert do we get a true parabolic trajectory Motion equations can be used in one dimension only

4 Types of Projectile Motion 3. Launched horizontally Equations Since velocity does not change in x direction, our average velocity equation works… vx = dx/t vy = viy + at dy = viyt + .5at2 Sample problem next or straight to cliff diving?

Sample Problem A stone is thrown horizontally from the top of a cliff with a velocity of 15 m/s. It takes 3 s for the rock to land. a) How high is the cliff? b) How far from the base of the cliff does the stone strike the ground?

Sample Problem, cont. A stone is thrown horizontally from the top of a cliff with a velocity of 15 m/s. It takes 3 s for the rock to land. a) How high is the cliff? Given Unknown Equation Substitute Solve Ask: How high is in x or y direction? Y, so we need givens for y. Ans 44.1 m

Sample Problem A stone is thrown horizontally from the top of a cliff with a velocity of 15 m/s. It takes 3 s for the rock to land. b) How far from the base of the cliff does the stone strike the ground? Given Unknown Equation Substitute Solve Ans 45 m

4 Types of Projectile Motion 3. Launched horizontally Cliff Diving on Mars vx vy v v = vx2 + vy2

4 Types of Projectile Motion 4. Launched at an angle (a = g) What do you notice about the - vertical motion? - horizontal motion?

4 Types of Projectile Motion 4. Launched at an angle, cont… Horizontal velocity Vertical velocity

4. Launched at an angle (cont)… acceleration

Kinematics of Projectile Motion

Draw position vectors http://www.physicsclassroom.com/reviews/vectors/vectorsprint.cfm

Draw acceleration vectors a = -9.8 m/s2 a = -9.8 m/s2 a = -9.8 m/s2 a = -9.8 m/s2 a = -9.8 m/s2 a = -9.8 m/s2 EVERYWHERE!!! a = -9.8 m/s2 a = -9.8 m/s2 http://www.physicsclassroom.com/reviews/vectors/vectorsprint.cfm

Draw velocity component vectors vy vx vy vx vx vy vy vx vx vx vy http://www.physicsclassroom.com/reviews/vectors/vectorsprint.cfm

Actual velocity resultant vectors vy v vx vy vx vx vy v vy vx vx v vx vy http://www.physicsclassroom.com/reviews/vectors/vectorsprint.cfm

Projectile Motion Summary Object has: Horizontal Uniform motion Vertical Acceleration due to Gravity affects motion

A hunter, a monkey and a coconut Doing it for real Shoot the Monkey

Question? Suppose a rescue airplane drops a relief package while it is moving with a constant horizontal speed at an elevated height. Assuming that air resistance is negligible, where will the relief package land relative to the plane? a. below the plane and behind it. b. directly below the plane c. below the plane and ahead of it http://www.physicsclassroom.com/mmedia/vectors/pap.cfm

It will take 4 seconds to fall 78.4 meters Another Question? Anna Litical drops a ball from rest from the top of 78.4-meter high cliff. How much time will it take for the ball to reach the ground? It will take 4 seconds to fall 78.4 meters

Worksheet