A car moving with 20m/s is applied with the brake to produce acceleration of 10m/s² when the driver observes a man crossing the road 18 m ahead. Will the car hit the man?
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A car moving with 20m/s is applied with the brake to produce acceleration of 10m/s² when the driver observes a man crossing the road 18 m ahead. Will the car hit the man?
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Explanation:
Answer
Given,
Speed=20m/s,d=50m,retardation=5m/s
2
Let the ppossible reaction time be t
s
So the car moves 20tm And applied breaks with retardation 5m/s
2
So, the total distance under retardation is ≤50m
Thus the distance under the application of retardation =
2×5
20
2
−0
2
=s
′
⇒s
′
=40m
Therefore, 20t
s
+40≤=50⇒20t
s
≤50−40⇒20t
s
=10⇒t
s
≤
2
1
≤0.5s
Answer:
no he will hit the man.
Explanation: