Home › JEE Advanced › Physics › Rotational Motion › A **yo-yo** (solid uniform cylinder) of mass $M$…
A **yo-yo** (solid uniform cylinder) of mass $M$, radius $R$ unwinds under gravity. Its downward acceleration is:
A$g$
B$g/2$
C$2g/3$
D$g/3$
Answer & Solution
Correct answer: C. $2g/3$
Newton: $Mg - T = Ma$. Torque about CM: $TR = I\alpha = (MR^2/2)(a/R)$ ⇒ $T = Ma/2$. Sub: $Mg - Ma/2 = Ma$ ⇒ $a = 2g/3$. Tension $T = Mg/3$.
Related questions
The branch describing the motion of a rotating rigid body about a fixed axis is rotationalSix washers on a light rod illustrate the moment of inertia of a system of:The more massive an object is, the more of this it has in linear motion:Unlike linear position measured in metres, angular position is measured in units that are:Acceleration caused by the change in direction of tangential velocity is called:Several torques acting about one axis are combined by finding their:The perpendicular distance from the axis to the line of the force is called the:The SI unit of torque is the newton multiplied by the: