Simple block kinematics problem

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SUMMARY

The discussion focuses on a kinematics problem involving Block A, which weighs 75 lbf, and experiences forces due to static and kinematic friction, both at 0.50. The objective is to determine the acceleration of Block A under a 25 lbf force for three scenarios: moving up the plane at 8 fps, moving down at 15 fps, and at rest. The relevant equation used is the sum of all forces equals mass times acceleration, and the angles involved are defined by cosine (4/5) and sine (3/5) ratios.

PREREQUISITES
  • Understanding of Newton's second law of motion
  • Familiarity with static and kinetic friction coefficients
  • Basic trigonometry, specifically sine and cosine functions
  • Knowledge of force diagrams and free body diagrams
NEXT STEPS
  • Calculate acceleration using the equation F = ma for different forces
  • Explore the effects of varying friction coefficients on acceleration
  • Learn about free body diagrams to visualize forces acting on Block A
  • Study the implications of angle measurements in kinematics problems
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone involved in solving kinematics problems, particularly those related to forces and motion on inclined planes.

jean28
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Homework Statement



Block A weighs 75lbf and the coefficients of static and kinematic friction between A and the plane are both 0.50. Determine the acceleration of A under the action of the 25 lbf force when the velocity at A is (a) 8fps up the plane, (b) 15 fps down the plane. (c) Zero.

Homework Equations



Sum of all forces = mass * acceleration

The Attempt at a Solution



I don't know where to start... the box is doing up a plane and it's cosine is 4/5 and its sine is 3/5.
 
Physics news on Phys.org
"Its cosine is 4/5 and its sine is 3/5". What is "its"?? Yes, I understand it is an angle but with the horizontal or vertical?
 

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