Question

A system consisting of two masses connected by a massless rod lie along the x-axis. A 0.4 kg mass is at a distance x = 2m while a 0.6 kg mass is at a distance x = 7 m. The x-coordinate of the centre of mass is:

Options

• 5 m

• 3.5 m

• 4.5 m

• 4 m

Answer 1

5 m

Explanation:

x_CM = `("m"_1"x"_1 + "m"_2"x"_2)/("m"_1 + "m"_2)`

Hence, x_CM = `(0.4 xx 2 + 0.6 xx 7)/(0.4 + 0.6)`

= `5/1`

= 5 m