Question

The tires of a 1500 kg car are 0.600m in diameter and the coefficient la of friction with the road and the surface are

Static friction: 0.800
Kinetic friction: 0.600
Assuming that the weight is evenly distributed on the four wheels, calculate the maximum torture that can be exerted by the engine onto a driving wheel without spinning

Answer 1

`1765.8\; {\rm N\cdot m}`, assuming that
`g = 9.81\; {\rm N\cdot kg^(-1)}` and that the vehicle is on a level surface.

Step-by-step explanation:

The weight of this
`m = 1500\; {\rm kg}` vehicle is
`m\, g = (1500)\, (9.81)\; {\rm N} = 14715\; {\rm N}`.

Under the assumptions, the normal force from the ground on this vehicle would be equal to its weight,
`14715\; {\rm N}`. Since this normal force would be evenly split between the wheels, the normal force on each wheel would be
`3678.75\; {\rm N}`.

As long as the wheels aren't spinning or slipping, friction between the wheels and the ground is considered "static". This type of friction is the same as that on a box that is stationary on a slope (static), and not the same as the friction on a box sliding along the slope (kinetic).

To find the maximum static friction on each wheel, multiply normal force by the coefficient of static friction
`\mu_{\text{s}}`:

`(0.800)\, (3678.75\; {\rm N}) = 2943\; {\rm N}`.

At a distance of
`r = 0.600\; {\rm m}` from the axis of rotation, the maximum torque on each wheel from static friction would be:

`(2943\; {\rm N})\, (0.600\; {\rm m}) = 1765.8\; {\rm N\cdot m}`.