TOC: SPEED= DISTANCE/TIME11/9/2015

MOTION

Occurs when an object changes its position relative to a reference point.

REFERENCE POINT – A place or object that can be used to determine if an object is in motion.

Distance vs. Time

Distance – How far did the object go?

Time – How long did it take you to get there?

20 miles

0.5 hours

SPEED

The distance an object travels per unit time

Average Speed = total distance (d) / total time (t)

s = d/t

Graphing Motion

Motion of an object can be plotted in a distance – time graph.

X-axis Time Y-axis Distance

Dis

tanc

e

Time

The slope of a line on a distance-time graph gives the speed of an object in motion

Handy Dandy Formula Triangle

D

S T

Cm, mm, km, miles

Sec, min, hr

Mph, km/hr,

m/s, cm/s

Your Practice Problems

1. Becky leaves home and rides a distance of 30 km. It took her 2.5 hours. What is her speed?

S = D / TS = 30 km / 2.5 hS = 12 km/h

D

T

Your Practice Problems

2. A speed boat is traveling at 100 km/hr. How many hours will it take for the boat to cover a distance of 115 km?

T = D / ST = 115 km / 100 km/hrT = 1.15 hr

S

D

Your Practice Problems

3. What is the speed of a helicopter that traveled 1200 miles in 7 hours?

S = D / T S = 1200 mi / 7 hrs S = 171.43 mph

D T

Your Practice Problems

4. A hot air balloon traveled 2.5 hours at a speed of 450 km/hr. What distance did it travel?

D = S x T D = 450 km/hr x 2.5 hr D = 1125 km

T

S

Your Practice Problems

5. An airplane leaves Orlando, Fl and travels 540 miles to Washington D.C. The flight takes 90 minutes. What is the speed of the plane?

S = D / T S = 540 mi / 90 min S = 6 mi / min

D

T

Your Practice Problems

Now, it’s your turn!! Complete your assignment by yourself

“Distance, Time, Speed Practice Problems” You need to show all the steps of the

problem (with units) When you are finished, you may use a

calculator to check your math! REMEMBER, you will not be using a

calculator on the Test