Question

A block of $10\,kg$ mass moving on a frictionless surface with speed $5\,ms^{-1}$ compresses a spring by $5cm$ and comes to rest. The force constant of the spring (in $Nm^{-1}$) is:

• A. $2 \times 10^5$
• B. $2.5 \times 10^5$
• C. $3 \times 10^5$
• D. $1.5 \times 10^5$
• E. $1 \times 10^5$

Hint:

Kinetic energy fully converts into spring potential on frictionless surface.

Answer 1

Answer: (E)