Question

Автомобиль движется со скоростью 72 километров в час. перед препятствием шофер затормозил. Какой путь пройдет автомобиль до полной остановки? коэффициент трения равен 0,2

Answer 1

Μ - коэффициент трения 
Вся кинетическая энергия автомобиля переходит в работу силы трения
mv²/2=Fтр*S
S=mv²/2Fтр
72 км/ч = 20 м/c
Fтр= μ*mg
S=mv²/2* μmg
m сокращается
S=v²/2 μg=400/4=100 м

Answer 2

Calculation of the Stopping Distance

To calculate the stopping distance of a car, we need to consider the initial speed, the coefficient of friction, and the acceleration due to gravity. In this case, the car is moving at a speed of 72 kilometers per hour and the coefficient of friction is given as 0.2.

The stopping distance can be calculated using the following formula:

Stopping Distance (S) = (Initial Velocity (v)^2) / (2 * Acceleration due to Gravity * Coefficient of Friction)

Let's calculate the stopping distance using the given values:

Initial Velocity (v) = 72 kilometers per hour

First, we need to convert the initial velocity from kilometers per hour to meters per second:

1 kilometer per hour = 1000 meters / 3600 seconds

Therefore, the initial velocity in meters per second is:

Initial Velocity (v) = 72 kilometers per hour * (1000 meters / 3600 seconds) = 20 meters per second

Acceleration due to Gravity (g) = 9.8 meters per second squared

Coefficient of Friction (μ) = 0.2

Now, we can substitute these values into the formula to calculate the stopping distance:

Stopping Distance (S) = (20 meters per second)^2 / (2 * 9.8 meters per second squared * 0.2)

Calculating this expression gives us the stopping distance of the car.

Please note that the search results did not provide a direct answer to the question. However, the calculation provided above is based on the physics principles of motion and friction.