Question

a ball of mass 100g is thrown vertically from the edge of a table with a speed of 1.3 m/s to compress a spring of a coefficient of 120 n/m. what is the height of the table if the spring compressed to 10.6 cm

Answer 1

Mass of ball, $m=100\space g=100\times10^{-3}\space kg=10^{-1}\space kg$

Speed of ball, $v=1.3\space m/s$

Spring constant, $k=120\space N/m$

Compression in spring, $x=10.6\space cm=0.106\space m$

Let height of the table $= h$

$\dfrac{1}{2}mv^2+mgh=\dfrac{1}{2}kx^2$

$h=\dfrac{(kx^2-mv^2)}{2mg}=0.601\space m$