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Grade 9General Physics

A car travels a certain distance with a speed of 40 m/s and returns with a speed u. If the average speed for the whole journey is 48 m/s, what is the value of u? Ans= 60 m/s.

Profile image of Ayushmaan
8 Years agoGrade 9
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1 Answer

Profile image of Arun
8 Years ago
Dear student
 
Avg speed = 2x y /(x+y)
48 = 2* 40 *u/(40+u)
 
1920 + 48 u = 80 u
32u = 1920
u = 60 
 
Hence u = 60 m/sec
 
 
Regards
Arun (askIITians forum expert)