wheels of diameters7cm and 14cm start rolling simultaneously from X and Y which are 1980cm apart,towards each other in opposite directions.both of them make same number of revolutions per second.both of them met after 10secs.what is the speed of smaller wheel?

• in 1 rev the smaller wheel goes 7pi
  in 1 rev the larger wheel goes 14pi
  let they make x rev per sec
  so in 10 sec they go 70*x*pi and 140*x*pi respectively
  by given eq, 210*x*pi=1980
  so x=3
  so speed of sm wheel=21*pi cm/sec
• 12 years agoHelpfull: Yes(24) No(5)
• x*7*10=x*14*10
  i.e their speed is in the ratio 1:2
  and bcoz time is same for both therefore the distance traversed by smaller wheel is 1/3 of 1980 i.e 660:1320.
  and speed=d/t.......660/10....=66 answer
• 12 years agoHelpfull: Yes(11) No(3)
• The Speed Ratio of Small:Large is 1:2 So, Dividing the total distance by 3 we get 660. this shows In 10 secs Small Wheel Could traveled 660cm and large wheel traveled 1320cm therefore speed of small wheel is 66cm/sec.
• 12 years agoHelpfull: Yes(7) No(3)
• given that both the wheels make same no. of revolution.
  let n be the no of revolution
  hence distance traveled by small wheel=7n*pi
  and distance traveled by larger wheel=14n*pi
  according to question...
  7n*pi+14n*pi=1980
  we get n=30
  so speed of smaller wheel=(7n*pi)/10
  on solving we get 66cm/sec
  
• 12 years agoHelpfull: Yes(4) No(0)
• @rakesh,@rishi,@sainath pls solve these ques and upload the answers as soon as possible!! pls pls!!
• 12 years agoHelpfull: Yes(0) No(2)