Question

A block of 200 g mass moves with a uniform speed in a horizontal circular groove, with vertical side walls of radius 20 cm. If the block takes 40 s to complete one round, the normal force by the side walls of the groove is ______.

Options

• 6.28 × 10^-3 N

• 0.0314 N

• 9.859 × 10^-2 N

• 9.859 × 10^-4 N

Answer 1

A block of 200 g mass moves with a uniform speed in a horizontal circular groove, with vertical side walls of radius 20 cm. If the block takes 40 s to complete one round, the normal force by the side walls of the groove is 9.859 × 10^-4 N.

Explanation:

Given, m = 200 g, r = 20 cm, T = 40 s

Using the expression

T = `(2pi)/omega`

`omega = (2pi)/40 = pi/20=3.14/20` radian/second

Normal force will provide the necessary centripetal force.

N = mrω² = `(200/100)(20/100)[3.14/20]^2`

= 9.859 × 10^-4 N.