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Home Q & A Board Science-Related Homework Help Physics
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AutoPenalti AutoPenalti
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4 years ago
Two packages are connected by a very light string that goes over an ideal pulley as shown in the figure. Package A has a mass of 3.0 kg and can slide along a rough plane inclined at 30° above the horizontal. The string acts on package A parallel to the surface of the plane. The coefficient of static friction between package A and the plane is 0.40. What minimum mass should package B have in order to start package A sliding up the ramp?
Textbook 
College Physics: A Strategic Approach

College Physics: A Strategic Approach


Edition: 3rd
Authors:
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fnce445fnce445
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4 years ago
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More solutions for this book are available here
2.5 kg

The parallel force= 3 ( 9.8 ) sin 30 = 14.7 N

 the frictional force is Ff = 0.4 * 3 * 9.8 * cos 30

F_f= 11.76 * cos 30 N

 so the total force = 14.7 + 11.76 * cos 30

=24.88N



 the tension in the string is equal to the total  force.

Tension=weight of package B.



 Weight = Mass * acceleration due to gravity

 Mass (9.8) = 14.7 + 11.76 * cos 30

 Mass = (14.7 + 11.76 * cos 30)/9.8

 =2.54 kg.
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Anonymous
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2 months ago
Help! The answer is missing an explanation...
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#3
2 months ago
Added it!
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