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
![k=(1)/(2)mv^2](https://img.qammunity.org/2023/formulas/physics/college/vca01wdm848xalqbn95u4ptnuplns6844l.png)
*Here m is the mass of the object
Substitute the known values in the above expression as
![\begin{gathered} 795=(1)/(2)m(3.5)^2 \\ m=129.79\text{ kg} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/high-school/4tfijak01i8pirfoohcmru799atxwo6d1m.png)
Hence, the mass of the object is m = 129.79 kg