Engineering Entrance Exams Application Date 2025 & Details

Centre Of Mass Of A Solid Cone - Practice Questions & MCQ

Edited By admin | Updated on Sep 18, 2023 18:34 AM | #JEE Main

Quick Facts

  • Position of centre of mass for solid cone is considered one of the most asked concept.

  • 3 Questions around this concept.

Solve by difficulty

Distance of the centre of mass of a solid uniform cone from its vertex is z0.  If the radius of its base is R and its height is h then z0 is equal to :

Concepts Covered - 1

Position of centre of mass for solid cone

Have a look at the figure of a solid cone

            

Since it is symmetrical about y-axis  

So we can say that  its x_{cm}=0 and z_{cm}=0

Now we will calculate its y_{cm} which is given by

y_{cm} = \frac{\int y.dm}{\int dm}

So Take a small elemental disc of mass dm of radius r  at a vertical distance y from the bottom as shown in the figure.

        

So  dm=\rho dv=\rho (\pi r^2)dy

Here \rho =\frac{M}{V}=\frac{M}{\frac{1}{3}\pi R^2H}  

And from similar triangle

  \frac{r}{R}=\frac{H-y}{H}

r=(\frac{H-y}{H})R

 

y_{cm} = \frac{\int y.dm}{\int dm}

y_{cm} = \frac{1}{M}\int_{0}^{H} y.dm = \frac{1}{M}\int_{0}^{H}y \frac{3M}{\pi R^2H}(\pi r^2)dy = \frac{H}{4}

So,   \mathbf{y_{cm} = \frac{H}{4}} from bottom O

Or, Centre of Mass of a solid cone will lie at distance \frac{3h}{4} from the tip of the cone.

Study it with Videos

Position of centre of mass for solid cone

"Stay in the loop. Receive exam news, study resources, and expert advice!"

Get Answer to all your questions

Back to top