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From the perspective of mechanical stress analysis, how to explain that the rotating tire rolls forward after the car starts? Or how to analyze the relationship between the tire and the ground Stress condition?
First of all, the driving wheel is rotated by the kinetic energy of the engine, and the rotation of the tire makes the tire surface move relative to the ground, but there is no sliding between the contact tire surface and the contact ground, so that the ground surface exerts forward static friction on the tire
As for the driven wheel, there is only friction on the rolling, and the friction is backward
It's too fast to copy the answers upstairs
The radius of the car wheel is 0.3 meters. How many meters does it go forward by rolling one circle? How many meters forward by rolling 1000 circles?
two × three point one four × 0.3 = 1.884 (m);
one point eight eight four × 1000 = 1884 (m);
A: it moves 1.884 meters forward in one circle and 1884 meters forward in 1000 circles
Is there static friction or rolling friction between the wheels and the ground when the car is running? Some books say that when driving, the relative instantaneous speed between the wheel landing place and the ground is zero, which is static friction; Some books say that the wheel and the ground are rolling friction. Which is right? The book says that the front and rear wheels are rolling friction
The front wheel is subject to rolling friction, and the rear wheel is subject to static friction and rolling friction (static friction is power, without which the car cannot move, and once it runs, it will be subject to rolling friction, which is resistance). If you don't understand, ask me again
A car's outer tire diameter is 9 decimeters. The wheels roll 1000 cycles per minute. How many kilometers does the car go per hour?
1 hour = 60 minutes
C=πd
=3.14 × nine
=28.26 (decimeter)
twenty-eight point two six × one thousand × sixty
=28260 × sixty
=1695600 (decimeter)
=169.56 (km)
A: the car travels 169.56 kilometers per hour
It is known that the angle of wheel rotation is directly proportional to the square of time. If it takes 0.8s for the first wheel rotation after the vehicle is started, Calculate the instantaneous angular velocity at 3.2s after the start of rotation
This is OK
A train advances at a speed of 20m / s. when it is 500m away from the tunnel, it whistles. When the driver hears the echo, how far is the locomotive from the tunnel entrance? The sound velocity is 340m / s
Time = 2 * (distance / speed) = 2 (500 / 340)
Answer = 500 - (2 (500 / 340) * 20)
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