Answer :
Given data
*The given energy is k = 795 J
*The speed of the object is v = 3.5 m/s
The formula for the kinetic energy of the object is given as
[tex]k=\frac{1}{2}mv^2[/tex]*Here m is the mass of the object
Substitute the known values in the above expression as
[tex]\begin{gathered} 795=\frac{1}{2}m(3.5)^2 \\ m=129.79\text{ kg} \end{gathered}[/tex]Hence, the mass of the object is m = 129.79 kg