# Engineering Mechanics

(Joyce) #1

(^90)  A Textbook of Engineering Mechanics
We know that distance between centre of gravity of the combined body from Py(),
11 2 2
12
60
wy w y
ww

• =

# × 3(90)^2 4150 ×

× = 40.5 mm. Ans.
EXERCISE 6.2

1. A hemisphere of 60 mm diameter is placed on the top of the cylinder having 60 mm
diameter. Find the common centre of gravity of the body from the base of cylinder, if its
height is 100 mm. [Ans. 60.2 mm]

2. A solid consists of a cylinder and a hemisphere of equal radius fixed base to base. Find the
ratio of the radius to the height of the cylinder, so that the solid has its centre of gravity at
the common face. [Ans. 2:1]
Hint. For stable equilibrium, the centre of the body should be below the common face or
maximum lie on it. So take the centre of gravity of the body at a distance (a) from the
bottom of the hemisphere.

3. A body consisting of a cone and hemisphere of radius (r) on the same base rests on a table,
the hemisphere being in contact with the table. Find the greatest height of the cone, so that
the combined solid may be in stable equilibrium. [Ans. 1.732 r]

4. Find the centre of gravity of a segment of height 77 mm of a sphere of radius 150 mm.
[Ans. 100 mm]

``Fig. 6.21.``