. If the static and kinetic friction between the tire and the inclined plane are 0.2 (static) and 0.15 (kinetic), calculate the maximum inclination angle so that the tire rolls without slipping

81.47°

Explanation:

The forward force on the tire is the horizontal component of its weight along the incline mgcosФ. The frictional force along the incline is μmgsinΦ where mgsinΦ is the vertical component of the tire's weight along the incline.

Since the tire rolls without slipping, then

mgcosФ = μmgsinΦ where μ = coefficient of kinetic friction = 0.15 (since the tire is in motion) and Φ is the angle of the incline.

So, mgcosФ = μmgsinΦ

mgcosФ/mgsinΦ = μ

μ = cosФ/sinΦ

μ = 1/tanФ

tanФ = 1/μ

Φ = tan⁻¹(1/μ)

substituting into the equation, we have

Φ = tan⁻¹(1/0.15)

Φ = tan⁻¹(6.667)

Φ = 81.47°

- measure reactants precisely. ( first choice)

- stir to the reaction take place. ( second choice)

- wait patiently until the reaction completes. ( fourth choice)

- make sure to recover as much copper as possible. ( last choice)

this could be newton#'s law of cooling. the cooling curve is exponential