# What is the kinetic energy of an object with a mass of 1 kg that has been in freefall for 1 s?

$48.02$ Joules
Kinetic energy ($K E$) is given by $\frac{m . {v}^{2}}{2}$, where $m$ is mass in kg and $v$ is velocity in meters. As the object of mass $1$ kg undergoes free fall for $1$ second, its velocity at the end of one second is given by $v = g \cdot t$, where $g$ is $9.8$ $\frac{m}{s} ^ 2$ i.e.
$v = 9.8 \cdot 1 = 9.8$ $\frac{m}{s}$, and hence $K E$ is given by
$\frac{1}{2} \cdot {9.8}^{2} = 48.02$ Joules.