Answer:
3.06 m
Explanation:
The work done by the man against the gravity is given by
[tex]W=Fh cos\theta[/tex] Where F is the force i.e. weight of the man and h is the displacement and [tex]\theta[/tex] is the angle between displacement and force
Since F=mg and [tex]\theta[/tex] is zero
W = mgh
Also, Work=power* time
Therefore, Power*time=mgh
Substituting power for 120 W, time for 20 seconds, g as 9.81 m/s2 and m as 80 Kg
120*20=80*9.81*h and making he the subject of the formula
[tex]h=\frac {120*20}{80*9.81}=3.058103976 [/tex]
Therefore, the height is approximately 3.06 m
