homework help > mechanical engineering > mechanical engineering q&a board > topic: mechanics dynamics ...

Q BgQuestion:

      
Novice
Karma Points: 25
Respect (100%):
posted by  Jomi on 7/3/2009 9:39:50 AM  |  status: Live  |  Earned Karma: 25

MEchanics Dynamics

Course Textbook Chapter Problem Needs by
N/A N/A N/A N/A N/A
Question Details:
The Crate has a Mass of 120kg, and the coefficients of friction between it and the sloping dock are μs =0.6 and μk =0.5.
A) What tension must the winch exert on the cable to start the stationary crate sliding up the dock?

B) If the Tension is maintained at the value determine in part(a) what is the magnitude of the crates velocity when it has moved 2m up the dock.

AAnswers:

Answer Question Ask for clarification
Guru
Karma Points: 2,803
posted by rooya(MNK) on 7/4/2009 8:47:13 AM  |  status: Live
Asker's Rating: Lifesaver   
Response Details:
 

m=120kg

W= 120*9.81N

μs = 0.6 ; μk = 0.5

Let  "T" be the tension in the string

F= Frictional force

ΣFy = 0

F = μsN

N=Wcosθ

N=120*9.81cos30

N=1019.48N

F=0.6*1019.48

F=611.69N

ΣFx = 0

T- Wsinθ -F =0

T = Wsinθ + F

T = 120*9.81sin30 + 611.69

T = 1200.29N
Answer Question Ask for clarificarion
Ask New Question

Join Cramster's Community

Cramster.com brings together students, educators and subject enthusiasts in an online study community. With around-the-clock expert help and a community of over 100,000 knowledgeable members, you can find the help you need, whenever you need it. Join for free today » How Cramster is different from tutoring »

Need Help In

Useful Links