Answer:
A. Refer to the figure.
B. The net force acting on the crate is
[tex]F_{net} = F_1 - F_2 = 317 - 173 = 144N[/tex]
C. We should first find the acceleration of the crate using the following kinematics equation:
[tex]v = v_0 + at\\6.5 = 0 + 5a\\a = 1.3 m/s^2[/tex]
Mass of the crate can be found by Newton’s Second Law:
[tex]F = Ma\\M = F/a = 144/1.3 = 110.7 kg[/tex]