Question

An air puck of mass 0.200 kg is tied to a string and allowed to revolve in a circle of radius 1.03 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of 1.22 kg is tied to it as seen in the figure below. The suspended mass remains in equilibrium while the puck on the tabletop revolves. What is the tension in the string? What is the force causing the centripetal acceleration of the puck? What is the speed of the puck?

Answer 1

a)

Since 1.22 kg mass is in equilibrium ,The Tension in the string is

T=mg= 1.22*9.8 =11.956 N

b)

The force causing the centripetal acceleration of the puck is the tension in the string i.e

F_c=T=11.956 N

c)

Since

F_c=m_puckV²/r

=>0.2*V²/1.03 =11.956

V=sqrt[11.956*1.03/0.2]

V=7.847 m/s