NAME: DATE: PERIOD: AP1 PHYSICS Freeall Notes Teacher Key - Physcsts DO NOT KNOW WHY objects all! But, we can escrbe HOW they all As they all, THEY GO FASTER Ths means that they ACCELERATE! What happens when objects all?!? They ACCELERATE at a CONSTANT RATE g - The Magc Number Lttle g s a shorthan or ACCELERATION DUE TO GRAVITY All LARGE OBJECTS hae a lttle g alue! Examples g s -1.67 m/s on the Moon g s -6 m/s on Jupter g s -9.81 m/ s on Earth *NOTE* - Lttle g s a measure o the strength o an objects GRAVITATIONAL FIELD! (More on ths later) Free Fall Facts - Drectons So g acts n the ownwar recton? g s negate ( - ) I an object alls n the ownwar recton? Dstance / splacement s negate ( - ) Velocty s negate ( - )
An object alls rom rest. What s ts elocty ater one secon? Two secons? Three Secons? at 0 ( 9.81m s )(1s ) 9.81m s 0 ( 9.81m s )(s) 19.6m s 0 ( 9.81m s )(3s) 9.43m s = 0 m/s t = 1 s = -9.81 m/s t = s = -19.6 m/s t = 3 s = -9.43 m/s t = 4 s = -39. m/s t = 5 s = -49.0 m/s Uses or g t = 0 s = 0 m = -4.9 m = -19.6 m = -44.145m = -78.4m = -1.5m An object alls rom rest. How ar has t allen ater one secon? Two secons? Three Secons? 1 t at 0 (0.5)( 9.81m s )(1s ) 4.9m 0 (0.5)( 9.81m s )(s ) 19.6m 0 (0.5)( 9.81m s )(3s ) 44.14m Object s roppe... Free Fall Facts - Summary V = 0 m/s a = g = -9.8 m/s s n ownwar recton, so s negate ( - ) Other Knematcs buzzwors relate to reeall Object s release... (whle hoerng / remanng statonary) Ex Hoerng helcopter, hot ar balloon, person on roo Object alls... Object slps rom...
Graphng Freeall Create a s. t, s. t, an a s. t graph or the ball as t alls urng the 5 secon tme span
So ar we hae looke at stuatons where: An object s roppe... An object s release... An object slps rom... In all cases, = 0 m/s What an object s thrown or re ownwar? What an object s kcke or tosse upwar? Free Fall Reste Free Fall Facts Drectons Agan... I s upwar? s poste ( + ) I s ownwar? s poste ( - ) ***REMINDER*** - Velocty an acceleraton are VECTORS! Must use + / - to ncate recton
Throwng Downwar An object s thrown ownwar rom the top o a 175 meter bulng wth an ntal spee o 10 m/s. a = -9.81 m/s = -10 m/s What acceleraton oes t experence? -9.81 m/s What s the object s ntal elocty? -10 m/s a an n SAME DIRECTION What s the object s elocty as t hts the groun? = -10 m/s = -175 m a = -9.81 m/s =? a 59.4m / s How long oes t take the object to ht the groun? t =? at t a 5.03s Throwng Upwar A cannon res a shot rectly upwar wth an ntal elocty o 50 m/s. t = s = +30.38 m/s t = 1 s = +40.19 m/s a = -9.81 m/s = +50 m/s What acceleraton oes the cannonball experence? -9.81 m/s What s the cannonball s ntal elocty? +50 m/s a an n OPPOSITE DIRECTIONS What s the object s elocty when t reaches the top o ts lght? MUST ASSUME top = 0 What s the maxmum heght o the cannonball? How long oes t take the cannonball to reach the top o ts lght? at t a 5.09s 1 t at 17m
Free Fall Facts Summary Object thrown / re / launche ownwar... 0 m/s, s negate a = g = -9.8 m/s an a n same recton so ncreases Object thrown / re / launche upwar... 0 m/s, s poste a = g = -9.8 m/s an a n OPPOSITE recton on way UP, so... ecreases UNTIL = 0 m/s (occurs @ max heght) an a n SAME recton on way DOWN, so... ncreases FROM = 0 m/s (@ max heght) untl t hts the groun... t up = t own