A man can complete a circular path of radius 7m in every 20seconds. find the distance and displacement in 40 seconds and 1 minute 10 seconds and 2 minute 5 seconds
Answers
Answer:
Given :
r = 7 m
1 full round = 20 sec
→ In 40 second he complete 2 round of circular path.
Distance = 2 × 2πr
= 2 × 2×22/7× 7
= 88 m
Displacement = 0 (starting and ending point are same)
→ 1 min 10 sec = 60 +10 sec = 70 second
70 second means 3 full round and one half round
Distance = 3×2πr + 1/2×2πr
= 6×22/7 ×7 + 22/7 ×7
= 132 + 22
= 154 m
Distance = 154 m
Displacement = 0 + diameter of circle
= 7+7
= 14 m
→ 2 min 5 sec = 60+60+5 sec = 125 sec
125 sec means 6 full round and 1/4 round
Distance = 6×2πr + 1/4×2πr
= 12×22/7 ×7 + 1/2×22/7 × 7
= 264 +11
= 275 m
Displacement = 0 + 1/4× 2πr
= 1/2 × 22/7 × 7
= 11 m
Explanation:
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Answer:
circumference of a circular path = 2πr= distance
radius of of a circular path = 7m
distance covered by a man by one round = 2πr
r= 7m
2πr = 2×22/7×7 = 44m
according to the question a man can cover circular path in 20 sec
so , he can cover 44m in 20 sec
Explanation:
velocity = distance/time taken
= 44/20= 11/5m/s
distance covered in 40sec = 2 ×44 88m
displacement = 0
(i) distance in 1min 10sec
v= s/t. ( v=11/5 )
11/5= s/1min 10 sec
11/5 = s/70
(cross multiplication)
5s= 11× 70
s= 11×70/5
s=154m
displacement = 0m (as man cmpleted 11 complete rounds)
(i) distance covered in 2min 5 sec
v= s/t. (v=11/5)
11/5 = s/2min 5sec
11/5 = s/ 125
(cross multiplication)
5s = 11× 125
s = 11× 125/5
s = 11× 25= 275m
displacement = 6.4m (after completing all circular rounds)