Question

An object moves from point P to point Q with an average speed of 60 m/s and immediately comes back from Q to point P with an average speed of 144 km/h . Calculate the average speed over the whole journey in m/s.

Answer 1

Hi
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let distance from P to Q be Xm

here we have two cases
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case1)
when object moved from P to Q

the average speed of object =60m/s
total distance travel=Xm
Time taken=Distance /speed
Time taken=X/60s
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case 2)
When object move from Q to P

the average speed of object=144x5/18=40m/s
total distance travel =Xm

Time taken=X/40s
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Total distance travel by object from Q toP and P toQ

Total Distance=X+X=2Xm
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Total Time taken by object frm Q to P and P to Q

Total Time=X/40+X/60=1/24 Xs
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So

Average speed=(2X/1/24X)m/s
= 48 m/s

hope it helps you

Answer 2

Explanation:

so here is the answer hope it helps you all