This question involves the concepts of work done and the frictional force.
a. Work done by the person is "692.82 N".
b. Work done by the frictional force is "490.5 N".
a.
Work done by the person can be given by the following formula:
[tex]W=FdCos\theta[/tex]
where,
W = work done by the person = ?
F = Force applied by the person = 80 N
d = distance traveled = 10 m
θ = angle between force and motion = 30°
Therefore,
[tex]W=(80\ N)(10\ m)Cos30^o[/tex]
W = 692.82 N
b.
Work done by the frictional force is given by the following formula:
[tex]W_f=fd\\W_f=\mu mgd[/tex]
where,
[tex]W_f[/tex] = work done by the frictional force = ?
μ = coefficient of friction = 0.5
g = acceleration due to gravity = 9.81 m/s²
Therefore,
[tex]W_f=(0.5)(10\ kg)(9.81\ m/s^2)(10\ m)[/tex]
[tex]W_f=490.5\ N[/tex]
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