Question

An ideal spring is used to fire a 2g block horizontally across a frictionless table top the spring has a spring constant to 80 N/m and is initially compressed by 3cm the speed of the block as it leaves the spring is what

Answer 1

$\frac{1}{2} \times 80 \times 0.03 {}^{2} = \frac{1}{2} \times 0.002 \times v {}^{2}$
v = 6

Answer 2

Here, given that, m=2g=0.002kg, x=3 cm=0.03m

WKT, total work done=change in kinetic energy, therefore,

1/2kx^2=1/2mv^2 (Spring force is in direction of x)

Solving these we will get,

V=6m/s

Thank u