1.

When a stick of mass m and length | = 0.6 m is released from vertical position (as shown in figure), then what is the velocity of its free end when it strikes the ground?​

Answer»

Answer:

Given:

Stick of MASS m , LENGTH = 0.6 m is released from vertical position.

To FIND:

Velocity of free end when it strikes the ground.

Concept:

The BASIC concept to be used is that : The whole potential energy at vertical position will be converted to Rotational Kinetic Energy in the horizontal position.

Calculation:

Let the free end of rod be v , we know that centre of mass of a rod is at its midpoint. so gravitational force will act at l = 0.3 m.

PE \: = \: KE

=  > mg(0.3) =   \dfrac{1}{2} I {\omega}^{2}

=  > mg(0.3) =   \dfrac{1}{2}  \times ( \dfrac{m {l}^{2} }{3} ) {\omega}^{2}

We know that ω = v/l , we can say :

=  >  \cancel mg(0.3) =   \dfrac{1}{2}  \times ( \dfrac{ \cancel m {l}^{2} }{3} )  \times { (\dfrac{v}{l}) }^{2}

Cancelling all other terms :

=  >  {v}^{2}  = 3 \times 3 \times 2

=  > v = 3 \sqrt{2}  \: m {s}^{ - 1}

So FINAL answer :

\boxed{ \red{ \huge{ \bold{v = 3 \sqrt{2}  \: m {s}^{ - 1} }}}}



Discussion

No Comment Found