$A$ block of mass $m$ moving with a velocity $v_0$ on a smooth horizontal surface strikes and compresses a spring of stiffness $k$ till mass comes to rest as shown in the figure. This phenomenon is observed by two observers:
$A$: standing on the horizontal surface
$B$: standing on the block
To an observer $A$, the work done by spring force is
negative but nothing can be said about its magnitude
$ - \frac{1}{2}mv_0^2$
positive but nothing can be said about its magnitude
$ + \frac{1}{2}mv_0^2$
Write the dimensional formula of $\frac {k}{m}$.
Two springs of spring constants $1500\, N/m$ and $3000\, N/m$ respectively are stretched with the same force. They will have potential energy in the ratio
A ball of mass $100 \,g$ is dropped from a height $h =$ $10\, cm$ on a platform fixed at the top of vertical spring (as shown in figure). The ball stays on the platform and the platform is depressed by a distance $\frac{ h }{2}$. The spring constant is.......... $Nm^{-1}$ . (Use $g=10\, ms ^{-2}$ )
A spring when stretched by $2 \,mm$ its potential energy becomes $4 \,J$. If it is stretched by $10 \,mm$, its potential energy is equal to
A block is attached to a spring as shown and very-very gradually lowered so that finally spring expands by $"d"$. If same block is attached to spring & released suddenly then maximum expansion in spring will be-