Free Fall and Projectile Motion Unit 2 Free Fall and Projectile Motion

Ex. An object moves in ________________ with an ____________________ and an ____________________ . (When graphing v vs. t, the area = _____________ .) 1 direction initial velocity vi acceleration a distance vf extra distance due to acceleration B dB = = ½ b h ½ t (vf – vi) ½ t (at) ½ at2 v vi A distance if there is no acceleration dA = L x W = vi t t t

Total distance d: d = dA + dB vit + ½ at2 If an object is not accelerating, then ___________ In this case, the last equation becomes: a = 0. vit + d = ½ 0t2 d = vit This last equation is really the same as: v = d/t after it is solved for: d = t v since v is ______________ when a = 0, then ______will be the same as _______. constant v vi

are all in your _____________ . PhysRT NOT is _______ in PhysRT One more equation: vf2 = vi2 + 2ad and these equations we studied before: v = d/t are all in your _____________ . a = Δv/t PhysRT vf = vi + at but: NOT v = vi + vf 2 is _______ in PhysRT All of these equations This is called: only describe motion:  _____________________ kinematics

Physics Reference Tables, last page: Which equation is not given? v = vi + vf 2

In these equations, all of the quantities are ______________ . This means they have _______________ and _______________ . Ex: If a ball is thrown with an initial speed of 7 m/s, use: vi = ________ if is thrown upward/to right vi = ________ if is thrown downward/to left. Ex. If a rocket moves a distance of 35 m, use: d = ________ if is moves upward/to right d = ________ if is moves downward/to left. vectors magnitude direction 7 m/s -7 m/s 35 m -35 m

Typical physics word problems involve objects moving in ____ direction that: 1 …. and end at another point with a __________ speed or velocity: ….begin at one point with an _________ speed or velocity: final initial d vi vf ….and move a distance or displacement ____ with an average speed _____ and at an acceleration _____ during a time interval of _____ . d v a t

Use units to help you solve problems: quantity symbol unit abbrev. of unit time distance or displacement speed or velocity acceleration s or sec second t meters d m v, vi vf, v meters per second m/s meters per second squared a m/s2

Word clues: 1. starts at rest  ______________ comes to rest  _______________ uniform motion  __________ , and _____________________ 4. constant velocity  _________________________ 5. constant speed in 1 direction  ___________ Acceleration will always be ________________ . It may be _________________, _________________ or _____ (still constant, but then _____________). vi = 0 vf = 0 a = 0 vi = vf = v see # 3 above see # 3 above constant positive negative see # 3 above

7. slows down: a and v are in _______________ directions 8. If an object collides with another object (like Earth), then its final speed is _________ ! In this case, "final speed" means the speed ___________________________ it hits. Whatever direction an object is moving is the direction of its _____________________ . 10. If an object changes direction, then, at that instant, only its ___________________________ MUST be zero. opposite NOT 0 the instant just before velocity speed and velocity