After striking the floor, a ball rebounds to 4/5th of the height from which it fell. Find the total distance it travels before coming to rest if it is dropped from a height of 100 metres.

• It means the ball looses 1/5 of its height i.e 20% from 1 to 4/5 then from 4/5 to (4/5 - (4/5 * 1/5)) = 16/25
  So it forms a G.P Series of..Multiplied by 2 because it goes up and comes down
  (120 +2*(120* 4/5 + 120*16/25 +120* 64/125 + ...+ till Infinity )
  => 120 + 2*120 * (4/5 )/ (1 - 4/5)
  =>120 + 960 =1080m
  Total distance travelled will be 1080m
• 10 years agoHelpfull: Yes(1) No(0)
• it forms a G.P Series of..Multiplied by 2 because it goes up and comes down
  (100 +2*(100* 4/5 + 100*16/25 +120* 64/125 + ...+ till Infinity )
  => 100 + 2*100 * (4/5 )/ (1 - 4/5)
  =>100 + 800 =900 m
  Total distance travelled will be 900m
• 8 years agoHelpfull: Yes(1) No(0)
• Infinite Geometric Series with a= 120 meters and r= 4/5
  
  
  ----------------------
  Total distance = Sum = a[1/(1-r)] = 120[1/(1/5)] = 600 ft
  ----------------------
• 11 years agoHelpfull: Yes(0) No(3)
• it forms a G.P Series of..Multiplied by 2 because it goes up and comes down
  (100 +2*(100* 4/5 + 100*16/25 +120* 64/125 + ...+ till Infinity )
  => 100 + 2*100 * (4/5 )/ (1 - 4/5)
  =>100 + 800 =900 m
  Total distance travelled will be 1080m
• 8 years agoHelpfull: Yes(0) No(0)