Flipping Phyic Lecture Note: Introduction to Acceleration with Priu Brake Slaing Exaple Proble a Δv a Δv v f v i & a t f t i Acceleration: & flip the guy and ultiply! Acceleration, jut like Diplaceent and Velocity, ha both Magnitude and Direction. Exaple Proble: Mr.p i driving hi Priu at 36 k/hr Eat when a baketball appear bouncing acro the treet in front of hi. Hi gut reaction i to la on the brake. Thi bring the vehicle to a top in.75 econd. What wa the acceleration of the vehicle? Known: v i 36 k hr Eat hr 3600 000 k 0 Eat; v f 0;.75; a? a Δv v f v i 0 0.75 5.743 5.7 Eat FYI: v i 36 k hr 000 i k 609 Ye, 3.374 wa a typo in the video, orry..374 i hr 003 Lecture Note - Introduction to Acceleration with Priu Brake Slaing Exaple Proble.docx page of
Flipping Phyic Lecture Note: A Baic Acceleration Exaple Proble and Undertanding Acceleration Direction Exaple Proble: Mr.p i riding hi bike at -4.3 k/hr when he begin pedaling the bike to caue a contant acceleration. If, after 6.4 econd, the bike i oving at -3.7 k/hr, what wa the acceleration of the bike? Known: v i 4.3 k hr hr 3600 000 k 3.97 ; v f 3.7 k hr hr 3600 000 k 6.583 ; 6.4; a? a Δv v f v i 6.583 3.97 0.407986 0.4 6.4 Coon Quetion: If the bike i peeding up how can the acceleration be negative? If an object i peeding up that ean the agnitude of the velocity i increaing. That ean that the acceleration and the velocity will be in the ae direction. In other word, if the velocity i negative and the object i peeding up, then the acceleration will alo be negative. People are uually ued to having poitive velocitie and therefore a negative acceleration would be oppoite the velocity and the object would be lowing down. 004 Lecture Note - A Baic Acceleration Exaple Proble and Undertanding Acceleration Direction.docx page of
Flipping Phyic Lecture Note: Walking Poition, Velocity and Acceleration a a Function of Tie Graph velocity / lope rie run Δy Δx Δvelocity acceleration ie The lope of a velocity veru tie graph i acceleration. review: The lope of a poition veru tie graph i velocity. tie A tangent line i a traight line that touche a curve at a point but doe not cro the curve. Exaple # Exaple # poition poition Exaple #4 tie tie Velocity / tie tie Acceleration / Acceleration / Velocity / tie tie 005 Lecture Note - Walking Poition, Velocity and Acceleration a a Function of Tie Graph.docx page of
Exaple #3 poition tie tie Acceleration / Velocity / tie page of
Flipping Phyic Lecture Note: Introduction to Uniforly Accelerated Motion with Exaple of Object in UAM Uniforly Accelerated Motion UAM i otion of an object where the acceleration i contant. In other word, the acceleration reain unifor; the acceleration i equal to a nuber and that nuber doe not change a a function of tie. Exaple of object in UAM: A ball rolling down an incline. A peron falling fro a plane. A bicycle on which you have applied the brake. A ball dropped fro the top of a ladder. A toy baby bottle releaed fro the botto of a bathtub. Technically, becaue of friction and a non-contant gravitational field, etc., they are not quite Uniforly Accelerated Motion, however, at thi point we will treat the a if they are, becaue it i cloe enough, for now. Thee are the equation that decribe an object in Uniforly Accelerated Motion: v f vi + a Δx vi + a v f vi + aδx Δx vi + v f There are 5 variable in the UAM equation: vi velocityinitial v f velocity final a acceleration Δx diplaceent changeintie My Suggetion. When you ue the UAM equation, you hould ue bae SI dienion; eter and econd. Here i how it work: There are FIVE variable in the UAM equation. There are FOUR UAM equation. If you know THREE of the variable, you can deterine the other TWO variable. Thi leave you with ONE happy phyic tudent. note: not one anwer. There can be ore than one anwer. A helpful definition: peanut gallery noun: a group of people who criticize oeone, often by focuing on inignificant detail. 006 Lecture Note - Introduction to Uniforly Accelerated Motion.docx page of
Flipping Phyic Lecture Note: Introductory Uniforly Accelerated Motion Proble A Braking Bicycle Exaple Proble: Mr.p i riding hi bike at.9 k/hr when he applie the brake cauing the bike to low down with a contant acceleration. After.0 econd he ha traveled 4.00 eter. a What wa hi acceleration and b what wa hi final peed? Known: vi.9 k hr 000 6.36 ; Δx 4.00;.0;v f?;a? hr 3600ec k Δx vi Δx vi + a Δx vi a a 0.5 4 6.36.0 a 4.75389 4.75 0.5.0 Part a Part b v f vi + aδx v f vi + aδx Note: I could alo have ued 6.36 + 4.75389 4.00.55968.56 v f vi + a 6.36 + 4.75389.0.55968.56 Δx Δx v f + vi v f + vi vi v f 4 6.36.55968.56 & gotten the ae anwer, again. vf.0 Or even Δx The reaon there are 3 equation we could ue i becaue after we have olved part a we now know four of the UAM variable and not jut 3. Hopefully Helpful Definition: Perpicaciou adjective: having or howing an ability to notice and undertand thing that are difficult or not obviou. ilk noun: a type of people or thing iilar to thoe already referred to. Pedantic adjective: of or like a pedant. Pedant noun: a peron who i exceively concerned with inor detail and rule or with diplaying acadeic learning. 007 Lecture Note - Introductory Uniforly Accelerated Motion Proble.docx page of
Flipping Phyic Lecture Note: Toy Car UAM Proble with Two Difference Acceleration Exaple Proble: A toy car tart fro ret and experience an acceleration of.56 / for.6 econd and then brake for. econd and experience an acceleration of -.07 /. a How fat i the car going at the end of the braking period and b how far ha it oved? Known: Part : vi 0;.6; a.56 ;.; a.07 ; v f?; Δxt? v f vi + a 0 +.56.6.496 vi Note: vf vi becaue they are at the ae oent in tie. The end of part i the beginning of part. Part : v f vi + a.496 +.07. 0.9 0. [anwer for part a] In order to olve part b, you need to realize that the total diplaceent i equal to the diplaceent for part plu the diplaceent for part. technically, the agnitude of the diplaceent becaue we don t have direction. So now we need to find each diplaceent individually and then add the together. v f + vi.496 + 0.6.9968 Part : Δx vi + a.496. +.07..4935 Total: Δxt Δx + Δx.9968 +.4935 3.49005 3.5 [anwer for part b] Part : Δx The following i an incorrect olution to part b Δxt v f + vi t v f + vi + 0.9 + 0.6 +. 0.9565 0.30 Becaue the acceleration i not contant for the whole proble; it i only contant for each part individually, not a a whole. 008 Lecture Note - Toy Car UAM Proble with Two Different Acceleration.docx page of
Flipping Phyic Lecture Note: Undertanding Uniforly Accelerated Motion We uually look at the dienion for acceleration a: a Δv Δv or every econd Today we are going to look at the dienion for acceleration a: a Exaple #: A ball i releaed fro ret and ha an acceleration of eter per econd every econd. a What i the velocity of the ball at t,, 3, 4 and 5 econd? b If the initial poition of the ball i zero, what i the poition of the ball at t,, 3, 4 and 5 econd? every econd, then the velocity will increae by every econd. At t 0, v 0 ; at t, v ; at t, v 4 ; at t 3, v 6 ; at t 4, v 8 & at t 5 v 0. Part b: Δx v i + a 0 + Δx Δx ; Δx 4 Part a: If the initial velocity of the ball i zero and the acceleration i Δx 3 3 9 ; Δx 4 4 6 ; Δx 5 5 5 Exaple #: A ball i given an initial velocity of -0 / and ha an acceleration of eter per econd every econd. a What i the velocity of the ball at t,, 3, 4 and 5 econd? b If the initial poition of the ball i 5 eter, what i the poition of the ball at t,, 3, 4 and 5 econd? and the acceleration i every econd, then the velocity will increae by every econd. At t 0, v -0 ; at t, v -8 ; at t, v -6 ; at t 3, v -4 ; at t 4, v - & at t 5 v 0. Part a: If the initial velocity of the ball i -0 Δx x f x i v i + a x f 5 0 + x f 5 + 0 + x f 5 + 0 + 6 ; x f 5 + 0 + 9 Part b: x 3f 5 + 0 3 + 3 4 ; x 4f 5 + 0 4 + 4 0095 Lecture Note - Undertanding Uniforly Accelerated Motion.docx ; x 5 f 5 + 0 5 + 5 0 page of
Flipping Phyic Lecture Note: Undertanding Intantaneou and Average Velocity uing a Graph Intantaneou Velocity: The velocity at a pecific point in tie. - The UAM variable Velocity Final and Velocity initial are intantaneou velocitie becaue they are at pecific point in tie. Average Velocity: The velocity over a tie period. - v Δx i an average velocity becaue i the tie period over which the velocity occur. Exaple Graph: 8.0# Poition'' 7.0# 6.0# 5.0#.0#.0#.0#.0# 5.0# 6.0# 7.0# 8.0# 9.0#.0#.0# 5.0# 6.0# 7.0# 8.0# Tie'' v Δx Δx x f xi x5 x0 0 v 0 5ec 0 t f ti t5 t0 5 0 5 V0-5 ec > An average velocity becaue it i a tie period fro 0 to 5 econd. v 5 0ec Δx x0 x5 7 5.0 t0 t 5 0 5 5 again, an average velocity Velocity at 6 econd, at 7 econd, at 9.8534 econd are all equal to.0 /. All are at a pecific point in tie and therefore intantaneou velocitie. Note: It the lope of the line, which we have hown to be velocity. v 0 7ec Δx x7 x0 7 5 0.94 0.9 t7 t 0 7 0 7 000 Lecture Note - Undertanding Intantaneou and Average Velocity uing a Graph.docx page of
Flipping Phyic Lecture Note: Graphical UAM Exaple Proble Poition'' Exaple Proble: Auing an initial poition of zero, coplete the epty graph. aue ig fig pleae note: in the proble, only the velocity veru tie graph wa given, the other two were blank We know the acceleration i contant and thi i a graph of Uniforly Accelerated Motion becaue the lope of the velocity v. tie graph i contant and the lope of a velocity v. tie graph i acceleration. 9.0# 8.0# 7.0# 6.0# 5.0#.0#.0# a.0#.0# Δv v f vi a v f vi v f vi + a Tie'' a Therefore the equation definition of acceleration: Velcoity'/' And the UAM equation: v f vi + a Are equivalent and we can ue either to find acceleration. 7.0# 6.0# 5.0#.0#.0# a Δv v f vi 6 0.0 t f ti 3 0 Therefore on the acceleration v. tie graph we draw a horizontal line with a lope of zero at a value of.0 /..0#.0# Tie'' Acceleration'/ ^' Δv.5#.0#.5#.0# The poition a a function of tie graph i lightly ore coplicated. We know: - The initial poition i zero, becaue it wa tated in the proble. - The lope of the line hould increae a tie increae becaue the velocity increae. In other word, it i an upward loping curve. - The lope of the poition v. tie graph tart at zero becaue the initial velocity i zero. - We can ue a UAM equation becaue the acceleration i contant. Now we need to pick oe tie and tart deterining diplaceent..0#.0# Tie'' v f vi v f vi t f ti Δx0 v v0 t t 0 0 0.0 Δx0 v v0 t t 0 4 0 0 4.0 Δx0 3 v3 v0 t 3 t 0 6 0 3 0 9.0 Δx 0.5# After you deterine your diplaceent, plot the point and then add the upward loping curve to connect the point. 00 Lecture Note - Graphical UAM Exaple Proble.docx page of
Flipping Phyic Lecture Note: Experientally Graphing Uniforly Accelerated Motion In the video a treet hockey puck i given an initial velocity to the left and the poition, velocity and acceleration a a function of tie are experientally deterined. The black quare are the experientally oberved data. In the poition and velocity a a function of tie graph, the blue curve/line i a bet-fit curve/line that bet approxiate and interpolate the data. 00 Lecture Note - Experientally Graphing Uniforly Accelerated Motion.docx page of