A single conservative force F(x) acts on a particle of mass m only along the x-a
ID: 1780950 • Letter: A
Question
A single conservative force F(x) acts on a particle of mass m only along the x-axis. Its associated potential energy function is U(x) = 12x2 - 60x + 25 in Joules and it is graphed below. The x-axis is in meters. Suppose the particle is placed at a point of equilibrium and is given a brief push in the positive x-direction. The push gives the particle 75 Joules of initial kinetic energy. What are the approximate x-coordinates of the particle’s turning points?A.1.0 m and 4.0 m B.-0.4 m and 5.4 m C.-0.7 m and 5.75 mD.0.0 m and 5.0 m E.none of the above
Explanation / Answer
F = - dU/dx = 24 x - 60 = 0
x = 2.5 m
U(2.5) = 12(2.5)^2 - 60(2.5) + 25 = - 50 J
at turning Point, KE = 0
Applying energy conservation,
PEi + KEI = PEf + KEf
- 50 + 75 = (12x^2 - 60x + 25) + 0
12 x^2 - 60x = 0
x = 0 and 5 m
Ans(D)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.