if the weight of the truck is inversely proportional to the square of its speed. then by percentage does its speed decrease if the

2 thoughts on “if the weight of the truck is inversely proportional to the square of its speed. then by percentage does its speed decrease if the”

1. hshhdhdhddnjdjdjnrjrnr

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2. Given info : if the weight of the truck is inversely proportional to the square of its speed. There is an increase in its weight by 44 %.

   To find : The percentage decrease in the speed of truck is …

   solution : let weight of truck is w and speed of it is v.

   a/c to question,

   w ∝ 1/v²

   ⇒w = k/v² …(1), where k is proportionality constant.

   now w is increased by 44 %

   so, new weight = w + 44 % of w = 1.44 w

   so, 1.44w = k/v’²

   ⇒v’ = √(k/1.44w) ….(2)

   now new speed of truck, v’ = √(k/1.44w) [ from eq (2) ]

   now percentage change in v = (v’ – v)/v × 100

   = {√(k/1.44w) – √(k/w)}/√(k/w) × 100

   = (1/1.2 – 1)/1 × 100

   = -0.2/1.2 × 100

   = -100/6

   = -16.67 %

   Therefore the percentage decrease in speed of truck is 16.67 %

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