Question

Masses of 2kg each placed at the corners B and A for a rectangular plate ABCD as shown in fig.A mass of 8 kg to be placed on the so that the centre of mass of the system should be at the centre O .Then the mass should be placed

Answer 1

Answer:

1 m from O on OE

Let the origin be @ Q.

x let the 8 kg mass be placed @ P

Coordinates : Q=(0,0)

A=(−2,−l/2)

B=(−2,+l/2)

P=(x,y) say.

Y

cm

=

M

2×−

2

l

+2×+

2

l

+8xy

=0 (given)

⇒0+8y=0⇒y=0

X

cm

=

M

2×−2+2×−2+x×8

=0

⇒−8+8x=0

⇒x=1m

∴ Point P is on OE 1 m from Q.

Ans : A