Velocity = Displacement Speed = Distance v=d/t d
Elapsed Time Elapsed Time v t
1) Solve the equation v = d / t for d :
d= K
2) Solve the equation v = d / t for t :
t= K
3) Find the unknown speed in each of the following problems:
a) Given: d = 24 km b) Given: d = 12 km
t= 6h t= 2h
Find: v= km/h K Find: v= km/h K
c) The US Navy has the world's fastest warship. By floating on a cushion of air, it can travel 85 km in just 0.50 hours.
What is its speed?
Given: d= km
t= h d = 85 km v=?
Find: v= km/h K t = 0.50 h
d) During the 1994 Winter Olympics in Calgary, Dan Jansen from the US skated 500 meters in 35.76 seconds.
What was his average speed?
Given: d= m
t= s v =?
Find: v= m/s K d = 500m
t = 35.76s
e) In 1988, Rick Mears won the Indianapolis 500 in 3.45 hours. What was his average speed during the 500 mile race?
Given: d= mi
t= h
Find: v= mi/h K v=? 500 mi
3.45 h
4) Find the unknown distance in each of the following problems:
a) Given: v = 55 km/h b) Given: v = 18 m/s
t = 3.2 h t = 12 s
Find: d= km K Find: d= m K
c) While flying a kite, Benjamin Franklin sees a flash of lightening. He begins counting, and 12 seconds later hears
a clap of thunder. Assuming the speed of sound is 340 m/s, how far away did the lightening strike?
Given: v= m/s d=? v = 340 m/s
t= s t=12s
Find: d= m K
d) The highest speed achieved by a standard nonracing sports car is 350 km/h. How far could the car travel in 0.250 hours
at this speed?
Given: v= km/h v = 350 km/h t =0.250 h
t= h d=?
Find: d= km K
e) In 1952, the ocean liner United States crossed the Atlantic Ocean in 4 days with an average speed of 66.0 km/h. At
this speed, what distance could it travel in exactly 4 days?
Given: v= km/h
t= day = h
v = 66.0 km/h
Find: d= km
K t = 4 days
d=?
5) Find the unknown time in each of the following problems:
a) Given: v = 55 km/h b) Given: v = 18 m/s
d = 350 km d = 72 m
Find: t= h K Find: t= s K
c) In the 1992 Summer Olympics a four-man German kayak team completed the 100 m course while maintaining
an average speed of .580 m/s. What was their winning time?
Given: v= m/s
d= m
Find: t= s K
d) An ostrich can run at speeds of up to 72 km/h. How long would it take an ostrich to run 1.5 km at this
speed?
Given: v= km/h
d= km v = 72 km/h
d = 1.5 km
Find: t= h K t=?
e) A cheetah is the fastest mammal on Earth. A cheetah was observed to run a distance of 550 m at a speed
of 100 km/h. How much time was required for the cheetah to run this distance?
Given: v= km/h
d= m = km
Find: t= h K
For a distance vs. time graph: speed = slope = rise / run
0 018 Kilometer Bicycle Race
0 0
20
18 20 2 4 1.5
16
14
Distance (km)
40 4 8 3
12
10 60 6 12 4.5 min
8
km/min
6 80 8 12 6
km/min
4
2 km/min
100 10 13 6
0
0 20 40 60 80 100 120 140 160 180 200 220
min
120 12 14 6
Time (minutes) Melisa
Katie
Ashley km/min
140 15 15 10
160 18 16 14
180 17 18
200 18
= slope = rise / run
Which girl had an the slowest
speed for the first half hour of
the race?
Which girl won the race?
Which girl had the fastest
speed at the start of the race?
How many minutes did Katie
rest during the race?
What was Katie's average
min
min speed for the first hour?
What was Ashley's speed
during the interval from 80 to
min
120 minutes?
What was the winning time for
the race?
What was Melissa's average
min velocity for the race?