An air puck of mass m1 is tied to a string and allowed to revolve in a circle of

Question

An air puck of mass m1 is tied to a string and allowed to revolve in a circle of radius R on a frictionless horizontal table. The other end of the string passes through a small hole in the center of the table, and a counterweight of mass m2 is tied to the string. The suspended load remains in equilibrium while the puck on the tabletop revolves. (Use the following as necessary: m1, m2, g, and R.)

(a) What is the tension in the string?
T=______

(b) What is the radial force acting on the puck?
F=______

(c) What is the speed of the puck?
v=______

(d) Qualitatively describe what will happen in the motion of the puck if the value of m2 is somewhat increased by placing an additional load on it.


(e) Qualitatively describe what will happen in the motion of the puck if the value of m2 is instead decreased by removing a part of the hanging load.

Explanation / Answer

its good that you havent given any values, so you cen figure it out yourself. (a) Look at the forces on the hanging mass. From those you can readily see that the tension in the string must equal the weight of the hanging mass, T = m2.g T = .... N (b)The only horizontal force acting on the puck is the tension in the string so this tension is the central force and is equal to the centripetal force, Fc = T = m2.g Fc = T = .... N (should be the same) (c) m1 v2 / R = m2 g (solve for v2) v2 = (m2 / m1) g R (solve for v) v = SQRT [ (m2 / m1) g R ] v = .... m/s (d)Since the value of m2g is greater than the force necessary to get m1 going in a circular path, m2 will go down, decreasing the radius of m1's path as it goes. The reduction in m1's path will mean that angular velocity of m1 will need to increase because of the conservation of angular momentum. (E)The opposite will happen - its angular velocity will decrease because the length is increase.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.