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  4. A body of mass m = 1 kg is moving in a medium and experiences a fractions force F = - kv, where v is the speed of the body. The initial speed is v0 = 10 ms-1 and after 10s, its energy becomes half of initial energy. Then, the value of k is

Q. A body of mass is moving in a medium and experiences a fractions force , where v is the speed of the body. The initial speed is and after 10s, its energy becomes half of initial energy. Then, the value of is

KEAM KEAM 2018Work, Energy and Power Report Error

Solution:

According to the question,

initial and final speeds of the body)
or or
Given,
or



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