Q.
A $1\, kg$ block collides with a horizontal weightless spring of force constant $2.75 \,N / m$ as shown in figure. The block compresses the spring $4 \,m$ from the free position. If the coefficient of kinetic friction between the block and the horizontal surface is $0.25$, find the speed(in $m / s )$ of the block at the instant of collision in $m / s$. $\left( g =10 \,m / s ^{2}\right)$
Work, Energy and Power
Solution: