- #1
Kudo Shinichi
- 109
- 1
HELP!A rolling without slipping problem
A solid cylinder of radius R and mass M has a string wrapped around it and is placed on its side on a horizontal surface. The free end of the string is pulled horizontally with a force F as shown in the figure. As the string unwraps, the cylinder rolls along the surface without slipping.
a) show that the acceleration of the center of mass is given by a_cm=4F/3M
b) what is the magnitude and direction of the frictional force acting on the cylinder?
c) what is the acceleration of the free end of the string?
diagram:
http://tinypic.com/view.php?pic=2qsw4kj&s=4
V_cc=0 and it is the velocity at reference frame of center to center
a) accelertaion of CM:
A_tot=sqrt((atan)2+(ac)2)
=sqrt((R*alpha)2)2+(R*(Vcc)2)
because vcc=0 therefore A_tot=R*alpha
4F/3M=4(M*alpha)/3M=4/3*alpha and R=4/3 in this case
b) the frictional force opposite to the applied force, and it is equal to the applied force, which is equal to M*alpha
c) the acceleration of the free end of the string would be same as the acceleration of the cylinder, which is R*alpha
I am not sure whether I did the problem correctly or not, can anyone help me with it? thank you very much.
Homework Statement
A solid cylinder of radius R and mass M has a string wrapped around it and is placed on its side on a horizontal surface. The free end of the string is pulled horizontally with a force F as shown in the figure. As the string unwraps, the cylinder rolls along the surface without slipping.
a) show that the acceleration of the center of mass is given by a_cm=4F/3M
b) what is the magnitude and direction of the frictional force acting on the cylinder?
c) what is the acceleration of the free end of the string?
diagram:
http://tinypic.com/view.php?pic=2qsw4kj&s=4
The Attempt at a Solution
V_cc=0 and it is the velocity at reference frame of center to center
a) accelertaion of CM:
A_tot=sqrt((atan)2+(ac)2)
=sqrt((R*alpha)2)2+(R*(Vcc)2)
because vcc=0 therefore A_tot=R*alpha
4F/3M=4(M*alpha)/3M=4/3*alpha and R=4/3 in this case
b) the frictional force opposite to the applied force, and it is equal to the applied force, which is equal to M*alpha
c) the acceleration of the free end of the string would be same as the acceleration of the cylinder, which is R*alpha
I am not sure whether I did the problem correctly or not, can anyone help me with it? thank you very much.