MOTION
- is a change in position of an object with respect to time
- any movement or change in position or place
- is always observed and measured relative to a frame of
reference and its change in position to another reference
frame
SPEED
-Distance an object travels in a unit of time
s=d/t
speed = distance/ time
Example: Bob drove to his parents house that was 60
kilometers away it took him 2 hours, How fast was he
traveling?
60 kilometers / 2 hours = 30 km/hr
or 30 kmh
How do we figure units?
the UNIT for speed is
Any distance unit over any time unit.
Some distance units examples: m, cm, km, etc.
Some time units examples are: hr, min, days, month,
years, etc.
***when expressing units with division a
forward slash means per
ex. mi/ h (miles per hour) or m / s or ft / h
Solving for another variable
-if s = d / t we can solve for any of these three
variables
-to solve for distance we would cross multiply both
sides by the time, cancel, and then solve
s=d/t
t * s = (d / t) *t (the t’s cancel)
to give you
d=s*t
- to solve for time you do the same with an extra step
s=d/t
t * s = (d / t) *t the t’s cancel
to give you d = s * t then you divide by s on both
sides
d/ s = s * (t/ s) s’s cancel
to give you
t=d/s
3 Types of Speed
1- instantaneous- speed at any specific
instance
2- average- total distance over a period of time
interval, accounts for speed variations during
time.
ex. 32 km +13 km = 45 km = total distance
2 h + 1h = 3h = total time
avg. speed = 45 km/ 3 h = 15 km/h
3- constant- when speed of an object does not
vary. ex. satellite
1. A boat is traveling at a speed of 70 km per hour. It has to travel
a distance of 210 km. How long will it take?
2. A car takes four hours to reach its destination. The distance was
340 miles. What was its speed?
3. A car travels 300 km in six hours. What is the speed of the car?
4. What is the speed of a jet plane that flies 7200 km in 9 hours?
5. The speed of a cruise ship is 50 km/hr. How far will it travel in
14 hours?
6. The speed of a rocket is 16,000 km/hr, and it will take 66 hours
to complete its mission. How far will it go?
7. What is the speed of a cyclist that travels 60 km in 2 hours?
8. A snail wants to participate in the Boston Marathon, a distance
of 26 miles. His top speed is 0.01 miles per hour. Assuming he
maintains top speed for the entire race, how long will it take him to
finish?
9. A rocket takes off at 8000 miles per hour and travels for 10 hours? What
distance has the rocket traveled?
Answer
these Q’s
then
make up 6
of your
own
and answer
them
All on one
paper