Answer:
m = 0.623 kg
Step-by-step explanation:
By the conservation of energy, we can write the following equation
![\begin{gathered} E_i=E_f \\ KE=PE \\ (1)/(2)mv^2=(1)/(2)kx^2 \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/agb1kou02hwvr37sn2xbukvorvjmz0eyje.png)
Where m is the mass, v is the speed, k is the constant of the spring and x is the compression.
Solving the equation for m, we get
![\begin{gathered} 2^\cdot(1)/(2)mv^2=2\cdot(1)/(2)kx^2 \\ \\ mv^2=kx^2 \\ \\ m=(kx^2)/(v^2) \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/9z120bukqbv50dlamjr7eeuwf4mg93iejo.png)
Now, we can replace k = 955 N/m, x = 3.5 cm = 0.0355 m, and v = 1.39 m/s to get
![\begin{gathered} m=\frac{(955\text{ N/m\rparen\lparen0.0355 m\rparen}^2}{(1.39\text{ m/s\rparen}^2} \\ \\ m=0.623\text{ kg} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/bi2ugc9ii34hdrpss97w2pdcl2tb9rxtnd.png)
Therefore, the mass required is 0.623 kg