Chapter 07, Problem 057 A 194 kg crate hangs from the end of a rope of length L

Question

Chapter 07, Problem 057 A 194 kg crate hangs from the end of a rope of length L 3.6 m. You push horizontally on the crate with a varying force to move it distance d 3.56 m to the side see the figure (a) What is the magnitude of when the crate is in this final position? During the crate's displacement, what are (b) the total work done on it, c) the work done by the gravitational force on the crate, and (d he work done by the pull on the crate from the rope? (e) Knowing that the crate is motionless before and after its displacement, use the answers to (b), (c), and (d) to find the work your force does on the crate.

Explanation / Answer

a)

sin(theta) = 3.56/13.6

So, theta = 15.2 deg

F = T*sin(theta)

T*cos(theta) = mg

So, F = (mg/cos(theta))*sin(theta) = mg*tan(theta)

= 194*9.8*tan(15.2 deg) = 516.5 N <----answer

b)

sin(theta) = 3.56/13.6

So, theta = 15.2 deg

So, the height it elevates , h = L*(1- cos(theta)) = 13.6*(1 - cos(15.2 deg)) = 0.476 m

Work done on it = mgh = 194*9.8*0.476 = 905 J

But total work done on it = change in KE = 0 <---------answer

c)

Work done by gravittational force = -905 J

d)

Work done by pull = 0

e)

Work done = 905 J

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.