What is the relationship between conservative work and potential energy change?
Question 2
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A conservative force does \(12\,\mathrm{J}\) of work. Find \(\Delta U\).
Question 3
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A particle returns to its starting point under a conservative force. What is the net work by that force?
Question 4
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Name two common conservative forces in introductory mechanics.
Question 5
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A conservative force changes potential energy from \(20\,\mathrm{J}\) to \(5\,\mathrm{J}\). Find the work done by the force.
Question 6
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A particle has \(K_i=8\,\mathrm{J}\), \(U_i=15\,\mathrm{J}\), and later \(U_f=6\,\mathrm{J}\). Find \(K_f\) if only conservative forces act.
Question 7
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Why can a potential energy function be assigned to a conservative force?
Question 8
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A block slides along two different frictionless paths between the same two heights. Compare work done by gravity.
Question 9
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A particle moves under a conservative force from A to B. Along one path the force does \(18\,\mathrm{J}\) of work. Along a second path from B back to A, find the work.
Question 10
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A particle moves from \(x=1\,\mathrm{m}\) to \(x=4\,\mathrm{m}\) under a conservative force with \(U(x)=3x^2\,\mathrm{J}\). Find the work done by the force.
Question 11
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A force field is \(\vec{F}=2axy\,\hat{\imath}+ax^2\,\hat{\jmath}\), where \(a\) is constant. Decide whether the force is conservative, find a potential \(U(x,y)\) with \(U(0,0)=0\), and find the work done by the force from \((0,0)\) to \((X,Y)\).
Question 12
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A particle of mass \(m\) moves in one dimension under the conservative force \(F(x)=-ax+bx^3\), with \(a>0\) and \(b>0\). It starts at \(x=0\) with speed \(v_0\). Construct \(U(x)\) using \(U(0)=0\), then classify the possible motion regimes as \(v_0\) varies.