8. How long will a man take to make a round of a circular field of radius 21 m, cycling at the
speed of 8 km/h?
Answers
Answered by
0
Answer:
From the question,
Radius of the circular field, r=21m
Cycling at the speed of =8km/h
=
3600
8×1000
m/s....[Because 1km=1000m,1hr=3600sec]
=
3600
8000
=
36
80
... [divide by 4]
=
9
20
m/s
Distance covered by the cyclist = Circumference of the circular field
=2πr
=2×
7
22
×21
=2×22×3
=132m
Time taken by the cyclist to cover the field = (Distance covered by the cyclist / Speed of the cyclist)
=
9
20
132
=132×
20
9
=33×
5
9
=59.4sec
Step-by-step explanation:
follow karlo kaam aunga
Answered by
1
speed = distance/time
here distance = circumference = 2πr
speed = 2πr/t
8000/3600 = 2π21/t (I have converted speed into m/s)
80/36 =42π/t
t = 36 x 42 x π/ 80
t = 9 x 42 π /20
t = 189 π
t = 18.9 x 22/7
t = 59.4 seconds
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