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Zorluk: OrtaFriction and Resistance

A delivery truck is attempting to climb a slippery, snow-covered hill, but its rear drive wheels begin to spin in place. The driver stops and shifts several heavy crates from the front of the trailer to a position directly over the rear drive axle. What is the primary physical reason this action helps the truck regain traction?

  1. It increases the normal force pressing the drive tires against the road surface, which increases the maximum available frictional force.Cevap
  2. B
    It causes the tires to flatten out and expand their contact surface area with the road, which is the main factor that creates more friction.
  3. C
    It increases the inertia over the rear wheels, which generates a forward reaction force to push the truck up the hill.
  4. D
    It adds mass to the drive axle, allowing the constant rotational force of the engine to produce a greater forward acceleration.

Cevap

The action increases the normal force pressing the drive tires against the road surface, which increases the maximum available frictional force.
Traction is the practical application of static friction between a tire and a road surface. Frictional resistance depends on two primary factors: the coefficient of friction (the slipperiness of the snow and rubber) and the normal force (the force pressing the two surfaces together). By shifting heavy cargo directly over the drive axle, the downward force on those specific wheels increases. This increases the normal force, which directly increases the maximum available friction, allowing the tires to grip the snow rather than spin.

Adım Adım Çözüm

1
Analyze the cause of the wheels spinning.
The driving force exerted by the engine exceeds the maximum static friction available between the tires and the snow, causing kinetic friction (slipping) instead.
To move forward without slipping, static friction must be greater than or equal to the driving force.
2
Determine the physical effect of shifting the crates.
Moving the heavy crates directly over the rear drive axle increases the concentrated downward weight on those specific wheels.
Weight distribution affects how much force is applied to different parts of the vehicle.
3
Relate the increased weight to frictional force.
The increased weight increases the normal force (FNF_N) pushing the tires into the ground. Since friction (Ff=μFNF_f = \mu F_N) is directly proportional to normal force, the maximum static friction increases.
Frictional resistance relies on the normal force; greater normal force yields greater traction.

Anahtar Kavram

The maximum force of static friction (traction) is directly proportional to the normal force pressing two surfaces together.
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Konular

Friction and Resistance

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