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Learn about projectiles, motion equations, and vector addition in physics with examples and practical applications. Explore horizontal and vertical motion components of launched projectiles.
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Projectiles- 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!)
Projectile motion • In the absence of air resistance, a projectile will have a constant horizontal velocity and thus a horizontal acceleration of zero (ax = 0) • The projectile will be accelerated downward by the force of gravity. The vertical acceleration of the projectile will be –9.8 m/s2 (ay = -9.8 m/s2 )
Projectile motion • Mr larson is in the cannon
***Projectile motion*** • It is important to realize that the horizontal component of projectile motion remains constant.
Projectile Equations • Y = Vyit + 1/2at2 • Vyf = vyi + at • Vyf2 = vyi2 + 2ay • X =vxit and vxi = vxf notice that there is no acceleration. Why? • Vyi = visinq • Vxi = vicos q
Example • A cannon is fired horizontally at 20 m/s. Notice what happens to its horizontal velocity and its vertical velocity.
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?
Projectile motion • Compare the horizontal motion of the gravity free path and the projectile motion. • Compare the vertical motion and the projectile motion.
Projectile launched at an angle from ground level • The raider qb(greg jones) passes a football with a velocity of 3 m/s at an angle of 10 degrees with the ground. How high does the football go? How long is the football in the air? How far does the football travel?
Example problem • Kristen throws adam off of a cliff that is 15 m high. she throws adam with a velocity of 12 m/s at an angle 33 degrees. How long is adam in the air? Find Adam’s range and max height.
Vector addition notes • Add head to tail. • The resultant is placed from the tail of the first vector to the head of the last vector. • Example1: A cat runs 4 m S and 2 m N. Find the resultant displacement. • Example2: An A-10 thunderbolt II (warthog) flies east with a velocity of 40 m/s. A strong wind pushes it north with a velocity of 10 m/s. Find the resultant velocity.
Example2: An A-10 thunderbolt II (warthog) flies east with a velocity of 40 m/s. A strong wind pushes it north with a velocity of 10 m/s. Find the resultant velocity. • Diagrams from www.glenbrook.k12.il.us/gbssci/phys