PROJECTILES (2D)

A projectile is any object that is in a state of freefall, or in other words an object that is only acted upon by the

force of gravity (we are assuming no air resistance in this class!)

EXAMPLES OF PROJECTILES

PROJECTILE MOTION

What velocity will horizontally projectiles have?

What acceleration will projectiles have vertically? What will the velocity look like? Displacement?

PROJECTILE MOTION

PROJECTILE MOTION

Is the horizontal motion of the projectile constant?

PROJECTILE MOTION

• Compare the horizontal motion of the gravity free path and the projectile motion.

• Compare the vertical motion and the projectile motion.

EXAMPLE

A cannon is fired horizontally at 20 m/s. N what happens to its horizontal velocity and its vertical velocity?

PROJECTILE EQUATIONS

• Vertical Equations• y = Voyt + 1/2gt2

• vf = voy + gt• vf

2 = voy2 + 2gy

• voy = v sin • Horizontal Equations• x = vxt • vx = v cos

• Notice the horizontal equation and there is no acceleration. Why?

EXAMPLE OF A HORIZONTALLY

LAUNCHED PROJECTILE

• A cannon is fired horizontally at 20 m/s on a 10 m tall cliff. How long will the cannon ball be in the air? How far from the base of the cliff will the cannon ball fall?

EXAMPLE PROBLEM

• An airplane is flying horizontally with a velocity of 250 m/s. If the pilot drops a water balloon out of the window and it lands a horizontal distance of 500m from the launch point. From what height was it dropped?

LAB: HORIZONTAL PROJECTILE

• If I roll a ball off of a table horizontally what effects how long it will take to hit the ground?•How fast I roll it?•How high the ball is?

PROJECTILE LAUNCHED AT AN ANGLE

PROJECTILE LAUNCHED AT AN ANGLE FROM GROUND

LEVEL• A quarterback passes a football with a velocity of 17

m/s at an angle of 38 degrees with the ground. How high does the football go? How long is the football in the air? How far does the football travel?

PROJECTILE AT AN ANGLE

• Zac be nimble, Zac be quick, Zac jumped over the candlestick with a velocity of 5 m/s at an angle of 30 degrees to the horizontal. Did Zac burn his feet on the .25 m-high candle? (Did Zac clear the candle, and by how much?)