Recent content by cyap

Wouldn't the friction be pointing to the right as the cylinder rotates clockwise?

Which is exactly why I would love to know how it was derived

$$Tr=(\frac{1}{2}M_2r^2)(\frac{a_2}{r})$$ $$T=\frac{1}{2}M_2a_2$$ $$M_1g-T=M_1a_1$$ $$M_1g-\frac{1}{2}M_2a_2=M_1a_1$$ Since according to "general knowledge" ##a_2=\frac{1}{2}a_1##: $$M_1g=M_1a_1+\frac{1}{4}M_2a_1$$ $$a_1=\frac{M_1g}{M_1+\frac{1}{4}M_2}$$

I don't seem to understand the difference of accelerations when a cord is wrapped around cylinders and spheres. What I was taught is that if the cord is wrapped around a cylinder/sphere, the acceleration of the cord and whatever it is connected to will be twice the acceleration of the cylinder...