A car of mass 1 metric ton starts from rest and accelerates at a speed of 72km/h in 20 seconds - Science - Force and Laws of Motion

Question

A car of mass 1 metric ton starts from rest and accelerates at a
speed of 72km/h in 20 seconds It the moves with a constant velocity
of 80 sec and is brought to rest in next 10 sec What is the total
distance covered by the car in the entire journey

Anshu Agrawal · Accepted Answer

Dear student,
Here, m=1 metric ton=1000kg u=0,v=72km/h=72×100060×60s=20m/s t=20s (i) From 0 to 20sec a=v−ut=20-020=1m/s2Distance covered in this part = 0
5×a×t2 =0
5×1×202=200m (ii) From 20sec to 100 secDistance covered with constant velocity = 20×80 =1600m(iii) From 100 to 110 seca=v−ut=0-2010=-2m/s2S =u22a=4002×2 = 100m( as v = 0)So total distance = 200+1600+100 =1900m
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A car of mass 1 metric ton starts from rest and accelerates at a speed of 72km/h in 20 seconds. It the moves with a constant velocity of 80 sec and is brought to rest in next 10 sec.What is the total distance covered by the car in the entire journey