- #1
PrudensOptimus
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The only force acting on a 2.0kg body as it moves along the positive x-axis has an x compenent Fx = -6x Newtons, where x is in meters. The velocity of the body at x = 3.0m is 8.0m/s.
(a). What is the velocity of the body at x = 4.0m?
(b). At what positive value of x wil the body have a velocity of 5.0m/s?
(a). Since K = W = Integral ( F dx )
and F = Fx = -6x
K = -3 (x ^2) evaluate from 0 to 4
= 48
m/2 v^2 = 48
v = 6.9m/s
correct?
(b). since m/2 v^2 = -3x^2
and v = 5
x = sqrt ( -25/3 )
is not right because it would give me a complex number...
Please advise!