Respuesta :
Answer:
Work done, W = 1.44 kJ
Explanation:
Given that,
Mass of boy, m = 74 kg
Initial speed of boy, u = 1.6 m/s
The boy then drops through a height of 1.56 m
Final speed of boy, v = 8.5 m/s
To find,
Non-conservative work was done on the boy.
Solution,
The work done by the non conservative forces is equal to the sum of total change in kinetic energy and total change in potential energy.
[tex]W=\dfrac{1}{2}m(v^2-u^2)+(0-mgh)[/tex]
[tex]W=\dfrac{1}{2}m(v^2-u^2)-mgh[/tex]
[tex]W=\dfrac{1}{2}\times 74\times (8.5^2-1.6^2)-74\times 9.8\times 1.56[/tex]
W = 1447.21 Joules
or
W = 1.44 kJ
Therefore, the non conservative work done on the boy is 1.44 kJ.
