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D = R x T Review 180 miles 75 mph 5 hours 100 miles

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Presentation on theme: "D = R x T Review 180 miles 75 mph 5 hours 100 miles"— Presentation transcript:

1 D = R x T Review 180 miles 75 mph 5 hours 100 miles
Motion Problems use the formula Distance = Rate x Time If the rate is 60 mph and the time is 3 hours, what is the distance? If the distance is 300 miles and it took 4 hours, what was the rate of speed? 180 miles 75 mph If the distance is 200 miles and the rate is 40 mph, what is the time? If the time was 2.5 hours and the rate was 40 mph, what was the distance? 5 hours 100 miles

2 What’s involved in a motion problem?
Two vehicles A slower one And a faster one!

3 What’s involved in a motion problem?
Going in the same direction. Or opposite directions!!

4 What’s involved in a motion problem?
Leaving at the same time. Leaving at different times

5 Step One: Draw the problem
It helps to find the distance needed to solve the problem. Look for: Starting Point,Direction, Departure Time Draw: Ex 1. Two cars start at the same point, at the same time, and travel in opposite directions. The slow car travels at 56 mph and the fast car travels at 60 mph. In how many hours, will they be 464 miles apart? Slow Car (56 mph) Fast car (60 mph) Start Total Miles: 464 miles Slow Car Distance + Fast Car Distance = 464

6 Drawing Practice Starting Pt: 360 miles apart.
Ex. 2 Two trains start at the same time from stations that were 360 miles apart and travel towards each other. The rate of the fast train exceeded the rate of the slow train by 10 miles per hour. At the end of 2 hours, the trains were still 120 miles apart. Find rate of each train. Starting Pt: 360 miles apart. Direction: Towards each other Starting Time: Same 120 miles Fast Train Slow Train Total Distance: 360 miles Fast Distance + Slow Distance = or Fast Distance + Slow Distance = 240

7 Fast Distance = Slow Distance
Drawing Practice Ex 3. How far can a man drive out into the country at the average rate of 60 miles per hour and return over the same road at 45 miles per hour if he travels a total of 7 hours. Starting Pt: Home & Unknown Direction: Away and back home Starting Time: A total of 7 hours Fast Rate Start Slow Rate Fast Distance = Slow Distance

8 50 100 60 120 100+120=220 Slow Rate Time Dist Fast Distance Equation 2
Ex. 2 Two trains start at the same time from stations that were 360 miles apart and travel towards each other. The rate of the fast train exceeded the rate of the slow train by 10 miles per hour. At the end of 2 hours, the trains were still 120 miles apart. Find rate of each train. Fill in what you know and find Guess Column Slow Rate Time Dist Fast SR+10 Distance Equation SD+FD=240 2 50 100 60 120 =220 Guess: Slow Rate Fast Rate = Slow Rate + 10

9 Slow Rate Slow Time Slow Dist Fast Rate Fast Time Fast Dist Distance
Ex. 2 Two trains start at the same time from stations that were 360 miles apart and travel towards each other. The rate of the fast train exceeded the rate of the slow train by 10 miles per hour. At the end of 2 hours, the trains were still 120 miles apart. Find rate of each train. KEEP GUESSING Slow Rate Slow Time Slow Dist Fast Rate SR+10 Fast Time Fast Dist Distance Equation SD+FD=240 50 2 100 60 2 120 =220 60 2 120 70 2 140 =260 55 2 110 65 2 130 =240 Slow Train Rate: 55 Fast Train: 65

10 SR ST SD FR FT FD Dist Equ 55 2 110 65 2 130 X 2 2X X+10 2 Ex. 2
On to ALGEBRA X is in Guess column SR ST SD FR SR+10 FT FD Dist Equ SD+FD=240 55 2 110 65 2 130 =240 X 2 2X X+10 2 2(X+10) 2X+2(X+10)=240 2x+2(x+10) = 240 2x + 2x + 20 = 240 4x+20 = 240 4x = 220 X = 55 Let x = slow rate Let x + 10= Fast rate Answer: Slow Train: 55 mph Fast Train: 65 mph

11 225=120? 225 60 2 120 45 5 Slow Rate Time Dist Fast Distance Equation
Ex 3. How far can a man drive out into the country at the average rate of 60 miles per hour and return over the same road at 45 miles per hour if he travels a total of 7 hours. Fill in what you know and find Guess Column Slow Rate Time Dist Fast Distance Equation SD=FD 225=120? 225 60 2 120 45 5 Guess: Slow Time Slow Time + Fast Time = 7

12 SR ST SD FR FT FD Distance Equation 45 5 225 60 2 120 225=120 4 180 3
Ex 3. SR ST SD FR FT FD Distance Equation SD=FD 45 5 225 60 2 120 225=120 4 180 3 180=180 135 240 135=240 X 45x (7-x) 60(7-x) 45x=60(7-x) 45x=60(7-x) 45x=420-60x 105x=420 X=4 Answer the Question! The man drove out 180 miles Let x = Slow Time Let 7-x = Fast Time

13 Wrapping It UP- Motion Distance Formula :
Why is it necessary to draw picture? Where does the x go in the Guess and Check chart? D = r x t To find Distance Equation In the Guess column


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