Question

A body of mass 10 kg is attached to a wire 0.3 m long. Its breaking stress is 4.8 × 10⁷ N/m². The area of cross-section of the wire is 10^-6m². The maximum angular velocity with which it can be rotated 111 a horizontal circle is ______.

Options

• 6 rad/s

• 5 rad/s

• 7 rad/s

• 4 rad/s

Answer 1

A body of mass 10 kg is attached to a wire 0.3 m long. Its breaking stress is 4.8 × 10⁷ N/m². The area of cross-section of the wire is 10^-6m². The maximum angular velocity with which it can be rotated 111 a horizontal circle is 4 rad/s.

Explanation:

m = 10 kg l = 0.3 m

B.S. = 4.8 × 10⁷ N/m²       A = 10^-6m²

∴ F = 4.8 × 10⁷ × 10^-6 = 48 N

`"mv"^2/r=48`

`"v"^2=(48xx0.3)/10=144/100`

`"v"=12/10=1.2  "m/s"`

`omega=1.2/r=1.2/0.3=` 4 rad/sec