Question

A $0.200kg$ mass is hung on a vertical spring which has spring constant $k=5.6N/m$, balanced such that the mass is motionless.
How much does the spring stretch relative to its original length as a result of the mass hanging on it?
Take the mass of the spring to be negligible.

• A. $0.04m$
• B. $0.11m$
• C. $0.35m$
• D. $0.70m$
• E. $0.84m$

Answer 1

The correct option is C $0.35m$

Given : $m=0.200$ kg $k=5.6$ N/m

The force exerted by the spring balances the weight of the hanging mass.

$\therefore$ $kx=mg$

OR $5.6\times x=0.200\times 9.8$ $⟹x=0.35$ $m$