- #1
Natko
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Homework Statement
A person running in a race has to pick up a mass equal to her own mass. Assuming she can still do the same
amount of work, her speed will be changed by a factor of
a. 0.25
b. 0.50
c. 0.71
d. 1
e. 2
Homework Equations
E=1/2mv2
The Attempt at a Solution
Since m is doubled, v2 should be halved. I'm stuck now. But the correct answer is 0.71. Can someone explain how?