Answer:
2812.66685 J
-2812.66685 J
Explanation:
m = Mass of person = 61 kg
L = Length of escalator = 7 m
h = Height of escalator = 4.7 m
The angle between the normal force and the distance traveled by the person would be
[tex]\theta=cos^{-1}\frac{h}{L}\\\Rightarrow \theta=cos^{-1}\frac{4.7}{7}\\\Rightarrow \theta=47.82^{\circ}[/tex]
Work done is given by
[tex]W=mgLcos\theta\\\Rightarrow W=61\times 9.81\times 7\times cos47.82\\\Rightarrow W=2812.66685\ J[/tex]
The work done by the escalator on the when the person rides it up is 2812.66685 J
While going down the angle will be
[tex]\theta=180-47.82\\\Rightarrow \theta=132.18^{\circ}[/tex]
[tex]W=mgLcos\theta\\\Rightarrow W=61\times 9.81\times 7\times cos132.18\\\Rightarrow W=-2812.66685\ J[/tex]
The work done by the escalator on the when the person rides it down is -2812.66685 J
A. The work done from lower to upper level is "2812.67 J".
B. The work done from upper to lower level is "-2812.67 J".
According to the question,
Person's mass, m = 61 kg
Escalator's length, L = 7 m
Escalator's height, h = 4.7 m
Now,
The angle will be:
→ θ = Cos⁻¹ [tex]\frac{h}{L}[/tex]
By substituting the values,
= Cos⁻¹ [tex]\frac{4.7}{7}[/tex]
= 47.82°
(A)
The work done will be:
→ W = mgLCosθ
By substituting the values,
= 61 × 9.81 × 7 × Cos 47.82°
= 2812.67 J
(B)
The angle while going down will be:
→ θ = 180 - 47.82°
= 132.18°
then,
The work done will be:
→ W = mgLCosθ
= 61 × 9.81 × 7 × Cos 47.82°
= -2812.67 J
Thus the responses above are correct.
Find out more information about work done here:
https://brainly.com/question/25573309
