Three point particles of masses $1.0 \; kg$,$1.5 \; kg$,and $2.5 \; kg$ are placed at three corners of a right-angled triangle of sides $4.0 \; cm$,$3.0 \; cm$,and $5.0 \; cm$ as shown in the figure. The center of mass of the system is at a point:

The centre of mass is a point:

The centre of mass of three particles of masses $1 \ kg, 2 \ kg$ and $3 \ kg$ is at $(2, 2, 2)$. The position of the fourth mass of $4 \ kg$ to be placed in the system so that the new centre of mass is at $(0, 0, 0)$ is:

Two objects of masses $200 \text{ g}$ and $500 \text{ g}$ possess velocities $10 \hat{i} \text{ m/s}$ and $(3 \hat{i} + 5 \hat{j}) \text{ m/s}$ respectively. The velocity of their centre of mass in $\text{m/s}$ is:

$(a)$ Centre of gravity $(C.G.)$ of a body is the point at which the weight of the body acts.
$(b)$ Centre of mass coincides with the centre of gravity if the earth is assumed to have an infinitely large radius.
$(c)$ To evaluate the gravitational field intensity due to any body at an external point,the entire mass of the body can be considered to be concentrated at its $C.G.$
$(d)$ The radius of gyration of any body rotating about an axis is the length of the perpendicular dropped from the $C.G.$ of the body to the axis of rotation.
Which one of the following pairs of statements is correct?

Give two examples of rigid bodies whose center of mass lies outside the material of the body.