Question

Please help with #4, thanks so much.#1A - 294 J to lift it#1B- 40 J when they accelerate#1C - 0J at a constant speed#1D - 80J of work when Luke throws Yoda#2 - Yoda travels 0.41 m from Luke before hitting the ground.#3 - The distance is 1.7 meters

Answer 1

In order to find the total work done upon Yoda, let's write the work in each case:

1A - Work done by Luke = 294 J

1B - Work done by Luke = 40 J

1C - No work

1D - Work done by Luke = 80 J

2 - Work done by gravity:

`Energy=mgh=20\cdot9.8\cdot1.5=294\text{ J}`

3 - Work done by friction force:

`\begin{gathered} F_f=\mu\cdot N\\ \\ F_f=\mu\cdot(m\cdot g)\\ \\ F_f=0.9\cdot20\cdot9.8\\ \\ F_f=176.4\text{ N}\\ \\ \\ \\ W=F\cdot d\\ \\ W=176.4\cdot1.7\\ \\ W=299.88\text{ J} \end{gathered}`

4 - The total work done upon Yoda is:

`\begin{gathered} W=294+40+0+80+294+299.88\\ \\ W=1007.88\text{ J} \end{gathered}`