Solving Motion Word Problems

You NEED to know how to use these equations (they will be given on assessments) Speed = d ÷ t Speed = d ÷ t Distance = s x t Distance = s x t Time = d ÷ s Time = d ÷ s Velocity = d ÷ t Velocity = d ÷ t Displacement = v x t Displacement = v x t Time = d ÷ v Time = d ÷ v Acceleration = ∆v ÷ Acceleration = ∆v ÷ t Velocity= a x t Velocity = a x t Time = ∆v ÷ a Time = ∆v ÷ a 

Steps when solving word problems 1. Write down what you are given in the question and what you are asked to find. 2. Write down the equation you will use. 3. Plug in what numbers you know. 4. Solve, and include the proper units. 5. Check your work

Interpreting Word Problems Time Time Units: seconds, minutes, hours Examples: the trip took 3 minutes; he traveled for 5 hours; it took 45 seconds Distance Distance Units: metres, kilometers Examples: she went/traveled/ran/drove/flew/biked 30 metres Speed Speed Units: m/s, km/h Words: the car was going 100km/h; the balloon rose at a speed of 10m/s Acceleration Acceleration Units: m/s 2 Words: the car accelerated 2m/s 2 ; the bike slowed down at a rate of -6m/s 2

Example #1 High speed elevators can go 7.11m/s. How much time would they need to go up 37.5m? High speed elevators can go 7.11m/s. How much time would they need to go up 37.5m? Speed = 7.11 m/s Distance = 37.5 m Time = ? Time = distance ÷ speed Time = 37.5 m ÷ 7.11 m/s Time = 5.27 seconds

Example #2 Megan was biking at a velocity of +5m/s. Then, she slowed down to a velocity of +2m/s in 25 seconds. What was her acceleration? Megan was biking at a velocity of +5m/s. Then, she slowed down to a velocity of +2m/s in 25 seconds. What was her acceleration? Vinitial = +5m/s & Vfinal = +2m/s Vinitial = +5m/s & Vfinal = +2m/s SO ∆V = +2m/s - +5m/s; ∆V = -3m/s Time = 25 seconds Acceleration = ∆v ÷ t Acceleration = ∆v ÷ t A = -3m/s ÷ 25s A = -3m/s ÷ 25s A = m/s 2 A = m/s 2