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Zorluk: KolayFriction and Resistance

A mechanic needs to move a heavy steel block across a flat concrete floor. Which of the following actions will successfully decrease the frictional resistance between the block and the floor?

  1. A
    Turning the block so it rests on its narrowest side to reduce the contact surface area
  2. Placing round steel pipes underneath the block to act as rollersCevap
  3. C
    Pressing downward on the top of the block while moving it to decrease its mass
  4. D
    Pushing the block with a sudden strike to eliminate the floor's opposing reaction force

Cevap

Placing round steel pipes underneath the block to act as rollers.
Rolling friction is significantly lower than sliding (kinetic) friction. By placing round steel pipes under the heavy block, the sliding motion is converted into a rolling motion, which drastically reduces the physical effort and resistance required to move the object.

Adım Adım Çözüm

1
Identify the type of friction currently acting on the block.
The block is sliding directly across the floor, so sliding (kinetic) friction is present.
Understanding the current resistance is necessary to evaluate ways to reduce it.
2
Evaluate the physical effect of each proposed action.
Changing surface area has no effect on friction magnitude. Pressing down increases friction. A sudden strike cannot eliminate reaction forces. Using pipes changes the friction type entirely.
Applying physical laws to each option isolates the effective method.
3
Compare the magnitude of sliding friction to rolling friction.
Rolling friction is significantly lower than sliding friction for heavy objects on hard surfaces.
This confirms that using pipes as rollers is the mechanically correct way to decrease resistance.

Anahtar Kavram

Friction and Resistance (Rolling vs. Sliding Friction)
Tahmini Süre:45s
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Konular

Friction and Resistance

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