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8 votes
8 votes
a person have a kinetic energy = 32, if the mass increase two times and the velocity decrease four times, What would be the kinetic energy?

User AmishDave
by
3.4k points

2 Answers

21 votes
21 votes

Answer:

4 J

Step-by-step explanation:

Original KE

  • KE = 1/2mv²
  • ⇒ 32 = 1/2mv²

Mass increases x 2

  • KE ∝ m
  • m x 2 ∝ KE x 2
  • 32 x 2
  • KE' = 64

Velocity decreases x 4

  • KE' ∝ v²
  • KE' x (1/4)² ∝ (1/4)²
  • KE' x 1/16 = 64 x 1/16 = 4 J

User Eggonlegs
by
3.4k points
20 votes
20 votes
ohAnswer:
4
Step-by-step explanation:
k.e= 1/2 mv²
K.E=1÷4×2
K.E= 1/8
K.E =32/8
K.E=4
User Mathias Weyel
by
3.2k points