Answer:
a) [tex]v\approx 7.671\,\frac{m}{s}[/tex], b) [tex]\Delta W_{g} = 500.157\,J[/tex], c) Lower final velocity, d) No.
Explanation:
a) The final velocity of the box is obtained by means of the Principle of Energy Conservation:
[tex]K = U[/tex]
[tex]\frac{1}{2}\cdot m \cdot v^{2} = m\cdot g \cdot \Delta h[/tex]
[tex]v = \sqrt{2\cdot g \cdot \Delta h}[/tex]
[tex]v = \sqrt{2\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (3\,m)}[/tex]
[tex]v\approx 7.671\,\frac{m}{s}[/tex]
b) The work done by gravity is:
[tex]\Delta W _{g} = m\cdot g \cdot \Delta h[/tex]
[tex]\Delta W_{g} = (17\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (3\,m)[/tex]
[tex]\Delta W_{g} = 500.157\,J[/tex]
c) The presence means that final velocity will be lesser at the bottom.
d) No, since work losses need to be calculated in order to calculate final velocity
