Speed
What is time?
 A particular moment
– 10:25 and 15 secs
 An interval of time
– 7pm to 7am
Time
 Measured in hours,
minutes, days, years
and seconds
 Metric only in science
 Always a number and
a unit -25 secs
What is distance?
 How far from one point
to another
 Unit of length
 Metric only in science
 Always a number and
a unit – 25 m
Speed
 Measure of how quickly an object moves from one place to
another
 An object that is not moving has a speed of zero - 0 m/s
 Distance traveled divided by the time taken
– 90 miles in 1.5 hours = 90mi /1.5 h = 60 mph
Velocity
 Speed of the object and the direction of its
motion
Speed
 Speed = v
– v is for velocity (speed with direction
added, traveled 75 mph south)
 Distance = d
 Time = t
Problems
A nascar driver has a car that is one of the
fastest on the circuit. If it travels 600 miles
in 4 hours, what is his cruising speed?
1. v = d/t
2. v = ?
d = 600 miles
t = 4 hrs
3. v = 600 mi/4 hrs
4. v = 150 mi/hr
The fastest car on Earth, a German-made Thrust
SSC, would win every Nascar race in America. If
it takes 0.5 hours (30 minutes) to travel 380
miles, what is its speed?
1. v = d/t
2. v = ?
d = 380 miles
t = 0.5 hrs
3. v = 380 mi/ 0.5 hr
4. v = 760 mi/h (mph)
The fastest train on Earth, the TGV from France, can
travel at faster speeds than trains in the United
States. During a speed test, the train traveled
800 miles in 2.5 hours. What is its speed?
1. v = d/t
2. v = ?
d = 800 miles
t = 2.5 hrs
3. v = 800 mi/ 2.5 hr
4. v = 320 mi/h (mph)
Spirit of Australia, a hydroplane boat, made speed
records by traveling 239 miles in 0.75
hours (45 minutes). What is its record-breaking
speed?
1. v = d/t
2. v =?
d =239 miles
t = 0.75 hrs
3. v = 239 mi/ 0.75 hr
4. v = 318.67 mi/h (mph)

How much time does it take for a bird
flying at a speed of 45 miles per hour to
travel a distance of 1,800 miles?
1. t = d/v
2. t = ?
d = 1800 miles
v = 45 mph
3. t = 1800 mi /45 mi/hr
4. v = 40 hrs

A cheetah runs at 60 mph for a distance of 0.5 miles.
How long does this take? Change answer to seconds.
1.
2.
t = d/v
t=?
d = 0.5 miles
v = 60 mph
3.
4.
t = 0.5 mi/ 60mph
t = 0.008 hr

0.008 hr x 60 min X 60 sec = 28.8 secs
1hr
1 min

A comet is cruising through the solar system at a
speed of 50,000 kilometers per hour for 4 hours
time. What is the total distance traveled by the
comet during this time?
1. d = vt
2. d = ?
v = 50,000 km/h
t = 4 hrs
3. d = 50,000 km/h X 4 hrs
4. d = 200,000 km

1.
2.
A runner runs 6.9 mph for 54 minutes. What distance did
the runner travel?
d = vt
d=?
v = 6.9 mph
t = 54 minutes
3.
4.
d = 6.9 mph X 54 min
d = 372.6 mph/min (Does this make sense)

Must change minutes to hours
–

54 min X 1 hour = 0.9 hr
60 min
d = 6.9 mph X 0.9 hr = 6.2 miles
Time vs distance Graph
 Shows distance traveled in relation to time traveled
 Line sloping upward – steady speed
 Change in upward slope = changing speed
– Steeper = faster
 Flat line – no motion
 Downward slope – returning to start
Time vs distance Graph
 Slope of a distance/ time graph or a position/time graph will
tell us the speed
 Slope = rise/run
 Slope = 60 miles/2 hrs
 Speed = 30 miles/hr
Average Speed
 Average of all speeds over time traveled
 Speed may not be constant
 Distance to San Antonio, Texas
– 1000 miles
 Time traveled
– 15 hours
 Average speed equals
– 66.66 mph
Instantaneous Speed
 Speed at a certain moment in time