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PhysicsN_b
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I drew up a quick picture in paint of a wheel under acceleration. This is the driving wheel of a RWD car. Am I missing any forces/drawn in the wrong direction?
Thanks.
Thanks.
If your model uses a non-zero value for angular inertia of the wheel then there's a small net torque on the wheel, most of the torque ends up accelerating the car. If your model uses a zero value for angular inertia of the wheel, then there is no torque due to angular acceleration of a massless wheel, and all of the torque ends up accelerating the car.PhysicsN_b said:I don't understand how I am not concerned with the torque applied on the wheel. If there is angular acceleration on the wheel, there has to be a torque applied.
A free body diagram is supposed to show only the forces acting on the wheel, and not the forces generated by the wheel.PhysicsN_b said:Also, the wheel has to be applying a forward force V(Fa) for the car to accelerate in speed correct, so at the axle there would be a forward force applied?
Close enough. In the real world, there would be rolling resistance, aerodynamic drag, energy losses in the drive train, but for a typical physics problem, it's good enough.PhysicsN_b said:Okay. So the only thing I need to get rid of is V(Fa) and 'say' that z is non zero and it should be perfect to be an example of a driving/accelerating wheel?
When a RWD (rear-wheel drive) car accelerates, the engine's power is transmitted to the rear wheels, causing the car to move forward. This movement creates a force called inertia that acts on the car's center of mass, which is typically located closer to the rear wheels. This force causes the rear wheels to push against the ground, resulting in a rotation of the wheels. As a result, the drawing of the wheel will appear elongated in the direction of acceleration.
The elongation of the wheel drawing is due to the principle of inertia. According to Newton's first law of motion, an object in motion will remain in motion unless acted upon by an external force. In this case, the force of acceleration causes the rear wheels to rotate and creates a perception of elongation in the wheel's shape.
No, there are other factors that can affect the drawing of the wheel under acceleration. These include the car's speed, the weight distribution of the car, and the condition of the road surface. The faster the car accelerates, the greater the force of inertia, resulting in a more elongated wheel drawing. The weight distribution of the car can also impact the amount of force applied to the rear wheels, affecting the shape of the wheel drawing. Additionally, the condition of the road surface can affect the traction of the rear wheels and the resulting rotation of the wheels.
When a RWD car decelerates, the force of inertia acts in the opposite direction, causing the rear wheels to rotate in the opposite direction. This results in the wheel drawing appearing compressed in the direction of deceleration.
Yes, there are differences in the drawing of the wheel for a FWD car. In a FWD car, the engine's power is transmitted to the front wheels, causing the front wheels to push against the ground during acceleration. As a result, the wheel drawing will appear elongated in the direction of acceleration, similar to a RWD car. However, during deceleration, the wheel drawing will appear compressed in the direction of deceleration, opposite to a RWD car.