Answer:
Efficency = 28%
Explanation:
We have the load has a weight of:
[tex]w =m*g\\w =12*9.81\\w = 117.72 [N][/tex]
Work in physics is defined as the product of force (weight) by distance.
[tex]W=w*d[/tex]
where:
W = work [J]
w = weight = 117.72[N]
d = distance = 5 [m]
[tex]W=117.72*5\\W=588.6[J][/tex]
Now power is defined as the relationship of work at a certain time.
[tex]P=W/t\\[/tex]
where:
P = power [W]
W = work = 588.6[J]
t = time = 30[s]
[tex]P=588.6/30\\P=19.62[W][/tex]
Now the efficiency of a machine is defined as the power output over the power input to the machine. The power input should always be greater than the power output.
[tex]efficency = \frac{Power_{out}}{Power_{in}}\\Efficeny = \frac{19.62}{70} \\Efficency = 0.28\\Efficency = 28%[/tex]
