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A 22 kg object PROBLEM?

A 22 kg object is acted on by a conservative force given by F = (-3.7)x + (-5.7)x^2, with F in newtons and x in meters. Take the potential energy associated with the force to be zero when the object is at x = 0.

a) What is the potential energy of the system associated with the force when the object is at x = 2.0 m?

b)If the object has a velocity of 3.7 m/s in the negative direction of the x-axis when it is at x = 5.0 m, what is its speed when it passes through the origin?

1 Answer

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  • 5 years ago

    a) Integrate F with respect to x. You'll have the usual + C arbitrary constant. Use the information that U = 0 when x = 0 to find C.

    Edit: F = -dU/dx. So U is the negative of the integral of F.

    b) Add the original kinetic energy to the potential difference (whether positive or negative) between starting and ending points to find the new kinetic energy.

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