What is Frictionless: Definition and 475 Discussions

The frictionless plane is a concept from the writings of Galileo Galilei. In his 1608 The Two New Sciences, Galileo presented a formula that predicted the motion of an object moving down an inclined plane. His formula was based upon his past experimentation with free-falling bodies. However, his model was not based upon experimentation with objects moving down an inclined plane, but from his conceptual modeling of the forces acting upon the object. Galileo understood the mechanics of the inclined plane as the combination of horizontal and vertical vectors; the result of gravity acting upon the object, diverted by the slope of the plane.However, Galileo's equations do not contemplate friction, and therefore do not perfectly predict the results of an actual experiment. This is because some energy is always lost when one mass applies a non-zero normal force to another. Therefore, the observed speed, acceleration and distance traveled should be less than Galileo predicts. This energy is lost in forms like sound and heat. However, from Galileo's predictions of an object moving down an inclined plane in a frictionless environment, he created the theoretical foundation for extremely fruitful real-world experimental prediction.Frictionless planes do not exist in the real world. However, if they did, one can be almost certain that objects on them would behave exactly as Galileo predicts. Despite their nonexistence, they have considerable value in the design of engines, motors, roadways, and even tow-truck beds, to name a few examples.The effect of friction on an object moving down an inclined plane can be calculated as





F


f



=

μ


k




F


N



,


{\displaystyle F_{\mathrm {f} }=\mu _{\mathrm {k} }F_{\mathrm {N} },}
where




F


f





{\displaystyle F_{\mathrm {f} }}
is the force of friction exerted by the object and the inclined plane on each other, parallel to the surface of the plane,




F


N





{\displaystyle F_{\mathrm {N} }}
is the normal force exerted by the object and the plane on each other, directed perpendicular to the plane, and




μ


k





{\displaystyle \mu _{\mathrm {k} }}
is the coefficient of kinetic friction.Unless the inclined plane is in a vacuum, a (usually) small amount of potential energy is also lost to air drag.

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  1. B

    Energy: Block sliding down frictionless ramp

    1. In Figure 8-49, a block is sent sliding down a frictionless ramp. Its speeds at points A and B are 1.90 m/s and 2.60 m/s, respectively. Next, it is again sent sliding down the ramp, but this time its speed at point A is 3.85 m/s. What then is its speed at point B? Figure 8-49...
  2. Z

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  3. J

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    Homework Statement This image: http://i52.tinypic.com/35i0j1k.jpg, assume the table surface and pulley to be frictionless. Please ignore the given a=1.96 in the photo as I will show how I reached that further below. Homework Equations F=ma The Attempt at a Solution Well, my stab at...
  4. R

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  5. C

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    I was solving this question in rotational mechanics (not asking for help). The author then goes to solve this using energy conservation, equating the final kinetic and rotational energy to the initial potential energy. Now, he obviously assumed the object rolled on the surface, which, if...
  6. G

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  7. C

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  8. F

    Force Exerted by Blocks on a Frictionless Surface

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  9. A

    Two masses connected by a pulley with a frictionless table

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  10. A

    Table and frictionless pulleys

    Figure 5-58 shows three blocks attached by cords that loop over frictionless pulleys. Block B lies on a frictionless table; the masses are mA = 4.40 kg, mB = 9.80 kg, and mC = 12.0 kg. When the blocks are released, what is the tension in the cord at the right? all i could do on this one is...
  11. A

    Frictionless pully and incline

    Figure 5-56 shows a box of mass m2 = 1.3 kg on a frictionless plane inclined at angle θ = 34°. It is connected by a cord of negligible mass to a box of mass m1 = 2.7 kg on a horizontal frictionless surface. The pulley is frictionless and massless. (a) If the magnitude of the horizontal force F...
  12. C

    Calculating Acceleration of a Box on a Frictionless Surface

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  13. J

    Solving Frictionless Horizontal Motion: Find Block's Speed

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  14. J

    Solving for Displacement in Frictionless Plane

    Homework Statement In a frictionless plane, a block of mass M is attached to a spring initially relaxed of constant k which is attached to a wall. A piece of gum of mass m is then horizontally thrown in direction to the block with velocity v_1 hitting it at time t = 0 in a perfectly inelastic...
  15. E

    Tension of 2 Bodies on a Frictionless Inclined Plane

    Homework Statement Figure 5-60 shows a box of dirty money (mass m1 = 2.7 kg) on a frictionless plane inclined at angle θ1 = 28°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.4 kg) on a frictionless plane inclined at angle θ2 = 64°. The pulley is...
  16. K

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    Homework Statement A 2.50kg object is moving on a plane with coordinates x=2t2-4 and y=3t3-3. Find the magnitude of the net force at t=2.00s Homework Equations \SigmaFy = 0 (no movement on y axis) \SigmaFx = m*a (mass x acceleration) The Attempt at a Solution Alright, first of all...
  17. M

    Determining spring's max compression on frictionless track

    Homework Statement A 0.280-kg block along a horizontal track has a speed of 1.30 m/s immediately before colliding with a light spring of force constant 43.6 N/m located at the end of the track. What is the spring's maximum compression if the track is frictionless? The Attempt at a...
  18. V

    Block sliding down wedge (w/ friction), wedge on frictionless floor

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  19. O

    Frictionless ramp question. Find angle.

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  20. A

    Finding height of frictionless roller coaster

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  21. E

    Pulley, two objects, frictionless plane; find acceleration and cable tension

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  22. Q

    Solving a Frictionless Massless Pulley Problem

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  23. C

    Linear Momentum - Person on a Plank on a frictionless surface

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  24. D

    Finding Tension in a Frictionless Ladder

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  25. J

    Two identical, uniform, frictionless spheres

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  26. J

    The total travel time along a frictionless path?

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  27. M

    Can you tie a knot in a frictionless rope?

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  28. C

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  29. S

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  30. Z

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  31. V

    Velocity final estimate on frictionless craft

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  32. M

    Two blocks on frictionless table, friction between blocks (Blocks side by side)

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  33. E

    Box on a Frictionless Incline

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  34. A

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  35. P

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  36. P

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  37. N

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  38. M

    Ball goes down a frictionless ramp

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  39. S

    Solving Frictionless Pulley System: Acceleration & Tension Force

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  40. T

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  41. P

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  42. L

    Machine part ABC is supported by a frictionless hinge

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  43. P

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  44. N

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  45. M

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  46. B

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  47. S

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  48. S

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  49. M

    Solving Frictionless System: Wood Block & Projectile

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  50. M

    Momentum: A bullet passing through a wooden block on a frictionless surface

    Homework Statement A wooden block with a length of 10 cm and a mass of 1 kg lies on an icy plane. A projectile with mass of 2 g hits the wooden block with velocity of 300 m/s and breaks through its center of gravity. How much are the final velocities of the wooden block and the projectile...
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