Answer:
72.75 kg
Explanation:
[tex]F[/tex] = force applied on a box = 750 N
[tex]m[/tex] = mass of the box
[tex]N[/tex] = Normal force on the box
[tex]\mu _{s}[/tex] = Coefficient of static friction = 0.66
From the force diagram, force equation along the vertical direction is given as
[tex]N = F Sin25 + mg[/tex]
[tex]N = 750 Sin25 + mg[/tex] eq-1
Static frictional force is given as
[tex]f_{s} = \mu _{s} N[/tex]
using eq-1
[tex]f_{s} = \mu _{s} (750 Sin25 + mg)[/tex]
For the box to move,
[tex]F Cos25 = f_{s}[/tex]
[tex]750 Cos25 = \mu _{s} (750 Sin25 + mg)[/tex]
[tex]750 Cos25 = (0.66) (750 Sin25 + m (9.8))[/tex]
m = 72.75 kg