Unit Linear Motion Linear Motion Key Term - How to calculate Speed & Ditance 1) Motion Term: a. Symbol for time = (t) b. Diplacement (X) How far omething travel in a given direction. c. Rate How much omething change per unit time ) Ma - amount of material preent in the object. d. Symbol for ma = (m) 3) Ditance - how far omething travel. e. Symbol for ditance = (d) f. Meaured in meter (m) and centimeter (cm) 4) How fat g. Speed (Alo called Average Speed) - How fat we are moving i. Symbol for peed = (v) ii. Equation to find average peed v = d/t ditance d= v*t time t = d/v b. Intantaneou peed = Speed at any one moment or intant in time. a. Speedometer in car read intantaneou peed. c. Velocity = How fat omething i moving in a given direction. a. Symbol for velocity = (v) Linear Motion Speed Word Problem 30) Seven tep to olve word problem: a. Read & circle key word b. What are you looking for? Place quare around it. c. Write equation d. Plug in number e. Solve problem f. Place unit on number g. Check anwer; doe it make ene 31) Word Problem: i. A racecar travel 00 km over hr, find the average peed? v = d/t = 00/ = 100 km/h ii. You walk 10 meter in 4 econd, find your peed. v = d/t = 10/4 =.5 m/ iii. You travel at 3 m/ for 10 econd, how far did you travel? Page 1 of 5
Unit Linear Motion d= v*t = 3 * 10 = 30 meter iv. A racecar travel at 30 m/ for 4 ec, how far did it travel? d= v*t = 30 * 4 = 10 meter v. A friend wave & yell at you. If the ound took 5.0 econd to reach you and the peed of ound i 340 m/, how far away wa your friend? d = vt = 340 * 5.0 = 1768 meter vi. vii. viii. The lowet animal (crab) travel at 5.70 km/yr, how long doe it take to travel 100 km? t = d/v = 100km/5.y km/yr = 17.5 yr You oberve lighting triking and then hear to ound 10 econd later. The peed of ound in air i 340 m/. How far where you from the lighting trike? d = vt = 340 m/ (10) = 3400 meter A racecar traveled 800 km over 3.45 hr, what i it average peed? V = d/t = 800 km / 3.45 hr = 31.8 km/hr (145 mph) Linear Motion Velocity 38) Intantaneou peed = Speed at any one moment or intant in time. a. Speedometer in car read intantaneou peed. 39) Velocity = How fat omething i moving in a given direction. a. Symbol for velocity = (v) b. Difference between peed and velocity i. Speed only tate the rate of motion. ii. Velocity include both peed and direction c. Example (i it peed or velocity?): i. Car traveling at 110 km/h peed or velocity? ii. iii. Car traveling at 110 km/h due north - peed or velocity? Peron walking north on Main Street at 3 m/ - peed or velocity? Page of 5
Unit Linear Motion iv. Peron walking to tore at 3 m/ - peed or velocity? d. Quetion: The peedometer of a car moving northward read 60 km/h. It pae another car that travel outhward at 60 km/h. i. Do both car have the ame peed? Ye ii. Do they have the ame velocity? No, different direction Linear Motion Acceleration How to calculate Velocity & Acceleration 40) Acceleration = the rate at which the velocity change over time. a. Symbol for acceleration = (a) b. Equation for finding acceleration: a = a = v t c. Acceleration occur when velocity change. i. Thi mean either a change in peed and/or change in direction 41) Deceleration = Negative acceleration (reduction in peed) 4) Problem for acceleration a. A car in traveling northwet increae it peed by 15m/ over a period of 8 econd; find the acceleration of the car. a = v/t = 15 m/ / 8 = 1.88 m b. A car traveling north increae it peed from 0 m/ to 10 m/ in econd, what i it acceleration? 10m 0m 10m a = 5 m c. A car in traveling outh increae it peed from 7 m/ to 5 m/ in 11 econd; find the acceleration of the car. 5m 7m 18m a 1.64 m 11 11 d. A truck in traveling eat decreae it peed from 30 m/ to 0 m/ in 5 econd; find the acceleration of the car. 0m 30m 10m a = - m 5 5 e. A plane traveling northeat increae it peed from 70 m/ to 100 m/ in 5 econd; find the acceleration of the plane. Page 3 of 5
Unit Linear Motion a= 100m 70m 5 30m 6 m 5 f. A plane traveling decreae it peed from 150 m/ to 100 m/ in 8 econd; find the acceleration of the plane. 100m 150m 50m a = -6.5 m 8 8 43) Linear Motion Practice WP a. What i the ymbol for ditance? d b. What i the ymbol for time? t Word Problem Show all work (equation, plug in, anwer) c. What i the ymbol for peed? v d. What i the ymbol for velocity? v e. What i the ymbol for acceleration? a f. A car travel 30 km for hour, what i it average peed? v = d/t = 30/ = 15 km/h g. A boy run at 3 m/ for 3 econd, how far did he run? d = vt = 3 (3) = 96 meter h. A girl run 1000 meter in 300 econd, what i her average peed? v = d/t = 1000/300 = 3.33 km/h i. An M1A1 army tank travel at 5 km/hr for 3 hour, how far did the tank travel? d = vt = 5 (3) = 75 km j. A peron walk at 500 meter in 00 econd, what i their average peed? v = d/t = 500/00 =.5 km/h Review of Acceleration k. Sport car increae it peed 5 m/ in 3 econd, what i it acceleration? a = v/t = 5 m/ / 3 = 8.33 m Page 4 of 5
Unit Linear Motion l. Sport car moving at 35 m/, hit brake, top in.0 ec, what i it deceleration? a= 0m 35m.0 35m -17.5 m.0 m. Car tart at 10 m/ and increae i peed to 8 m/ in 5 econd, what i it acceleration? 8m 10m 18m a = 3.6 m 5.0 5.0 Page 5 of 5