Force needed to pull a block up an incline.

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SUMMARY

The force required to pull a 20 kg block up a 30-degree incline at a uniform slow speed, with a coefficient of kinetic friction of 0.20, is calculated by balancing gravitational and frictional forces. The gravitational force acting down the incline is 98 N, while the frictional force opposing the motion is 34 N. To maintain constant speed, the applied force must exceed the net force of 64 N, which is the difference between gravitational and frictional forces. The applied force should also be directed at an angle equal to the angle of friction to optimize efficiency.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic knowledge of trigonometry
  • Familiarity with the concepts of friction and inclined planes
  • Ability to perform vector resolution of forces
NEXT STEPS
  • Study the principles of static and kinetic friction in detail
  • Learn about vector resolution techniques in physics
  • Explore the effects of different angles of incline on force calculations
  • Investigate real-world applications of inclined planes in engineering
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Students studying physics, particularly those focusing on mechanics, as well as educators looking for practical examples of force calculations on inclined planes.

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Homework Statement


Calculate the force needed to pull a mass of 20 kg at a uniform slow speed up a plane inclined at an angle of 30 with the horizontal if the coefficient of kinetic friction is 0.20.

Homework Equations


WN= w cos \vartheta
WT= w sin \vartheta
\mus= tan\vartheta

The Attempt at a Solution



I don't even know how to get started.
 
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If the block is moving at a constant speed then you know that there is no net force acting on the block.
 
Last edited:
so the friction force is
(.2)(20)(9.8)(cos 30) ?

and the gravitational force is
(20)(9.8)(sin 30) ?

i got 34 N for friction and 98 N for gravitational.

are they supposed to equal zero? or do i add them together to find the force i need to overcome? or could i just overcome the strongest?
 
So what force is needed to make them balance?
 
okay, so 34 N for friction pull the box up the slope, and 98 N gravity pull down.

98 N - 34 N = 64 N needed to equalize them, and more than 64 to make it move uphill?
 
What direction will the friction be acting in if the box is being pulled up the slope?
 
What is the direction of the force applied and whether the friction will depend on that direction.
 
If the minimum force needed is required than the force must be applied at an angle equal to angle of friction [tan^-1 (u)] with the incline.
 

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