distance speed and time calculating speed hrs and min calculating distance speed distance or time :...
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Distance Speed and Time
Calculating Speed
Hrs and Min
Calculating Distance
Speed Distance or Time : Which Operation
Hrs and Min
Calculating Time Hrs and Min
Hrs and Min : Intro
Speed Distance Time
Distance = Speed x Time
S = D ÷ T
Speed = Distance ÷ Time
D = S x T
T = D ÷ S
Time = Distance ÷ Speed
D
S T
Units
DST … Distance
D
S TX
To find Distance formula Cover D in DST triangle
T
=
S
D
Distance = Speed x Time
D = S x T
Examples
DST …. Speed
D
S TS = D ÷ T
Speed = Distance ÷ Time
÷
To find Speed formula Cover S in DST triangle
S =
D
T
= D T
Examples
DST ….. Time
D
S TT = D ÷ S
÷
To find Time formula Cover T in DST triangle
DT = D T
S
=
Time = Distance ÷ Speed
Examples
Units
S
D
T
Speed is the “key” when checking units
A speed of 60 mph is
60 miles
1 hour
60 mph
60 milesin 1 hour
Distance must be in miles
Time in hours
Units
S
D
T
Speed is the “key” when checking units
A speed of 12m/s is
12 m
1 sec12 m/s
12 metre
in 1 second
Distance must be in metres
Time in seconds
Units
S
D
T
60 km
1 hr60 km/hr
60 km
in 1 hour
Speed is km
/ hr
Units
S
D
T
25 cm
1 sec25 cm/s
25 cm
in 1 sec
Speed is cm
/ sec
60What’s the speed limit?
At this speed, how far would
you travel
in 1 hour?
60 miles per hour
60
1 2 3 4 hrs
0
120
60
180
60
Same distance for next hour
60
After 2 hrs ….. 60 x 2 = 120
After 3 hrs….. 60 x 3 = 180
45 1 hour?
miles per hour
45
1 2 3 4 hrs
0
90 135
45 x 1 = 45
45
2 hour? 45 x 2 = 90
3 hour? 45 x 3 = 135
4 hour? 45 x 4 = 180
180
Start Next
Rule for Distance
To find the distance travelled at a speed of S you multiply by the time taken for the journey
Distance
Speed Time= x
D S T= x
The next slide shows how to get this FORMULA from a DST triangle
Distance =
120
6D
Tx TS
Time = 6 hourSpeed = 120 km/hr
Find rule for Distance
720 km
D
S
=
x
D =
x
6120D =
Distance=
D
S TX TS
Time = 3 hr
D = S x T
60 X 3Speed= 60mph
Find Distance
D = S x T
D =
D = 180 miles
What can you find
1215
D
S X T
Time = sec
D = S x T
X
Speed= m/s
180 miles
15 12
D ==
Can find distance
Finding Distance
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
100 km/hr
hr
Distance
D = S x T
x
S = D ÷ T
T = D ÷ S
D= km
÷÷
Clear
minT= 4 h
r
hr
min
Parts of an Hour
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
New Speed
Clear
¼ ½ ¾
0.25
1
60
1
min
dec
5
8= 5 ÷ 8 = 0.625
9 18 27 360 Distance Travelled
D = 36 x 0.75 = 27
hour
Speed = 36 mph
D = S x T
Parts of an Hour
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
New Example
Clear
15
30 45
0.25
0.5 0.75 1
60 min
dec
Speed = 32 mph
D = S x T =
2 hrs
¼ ½ ¾ 1 hour
30 min
= 2.5 hrs
=
3 hrs 15 min = 3 +0.25 hrs = 3.25 hrsExample
Finding Distance – Hrs and Min
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
32 km/hr
3 hr
Distance
D = S x T
x
S = D ÷ T
T = D ÷ S
D= km
÷÷
Clear
15 minT= h
r
hr
min
Finding Speed
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
New Example
Clear
A train took hours to travel a distance of miles. If the train was travelling at the same rate then the speed in miles per hour is
4
hour
= 180
hour
= 180 ÷ 4 = 45
opposite of x is ÷ Each hour the train travels miles.
Speed
= Distance ÷ Time
SD
T=
4 180
x
45
Speed = 45 miles per hour
Finding Speed
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
km/hr
hr
D = S x T
x
S = D ÷ T
T = D ÷ S
D= 400 km
÷÷
Clear
minT= 4 h
r
hr
min
New Example
Finding Speed … Hrs & Min
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
km/hr
1 hr
D = S x T
x
S = D ÷ T
T = D ÷ S
D= 96 km
÷÷
Clear
30 minT= h
r
hr
min
New Example
Finding Time
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
20 km/hr
hr
Find Time
D = S x T
x
S = D ÷ T
T = D ÷ S
D= 80 km
÷÷
Clear
minT= h
r
hr
min
Finding Time Hrs Min
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
x
T
D
S
T=
S=
36 km/hr
hr
Find Time
D = S x T
x
S = D ÷ T
T = D ÷ S
D= 198 km
÷÷
Clear
minT= h
r
hr
min
Finding Speed , Distance or Time
0 1 2 3 4
5 6 7 8 91÷4
C
.
÷x
0.25+ On
²
-
Ans
=
√(-)
x
T
D
S
40
80
T=S=
40 km/hr
hr
D or S or T
x
T = D ÷ S
T = 80 ÷ 40
T= 2
D= 80 km
÷÷
Clear
minT= h
r
hr
min
D S T Hrs
D S T Hrs Min
Parts of an Hour
0 1 2 3 4
5 6 7 8 9
C
.
÷x
0+ On
²
-
Ans
=
√(-)
New Example
Clear
1
0.5
0.250.75
30
45 15