Question

Визначити, з яким прискоренням гальмував автомобіль, якщо при швидкості 72 км/год він зупинився через 3с, а коефіцієнт тертя між гумою та асфальтом 0.6. Виконайте задачу та малюнок до неї. НАПИСАТИ ПОВНИЙ РОЗВ'ЯЗОК З РОЗ'ЯСНЕННЯМ. ​

Answer 1

Ответ:

6,7 м/c²

Объяснение:

Vo=72 kм/год=20 м/c;

t=3 c;

μ=0,6

a  ?   a=V/t=20/3=6,7 м/c²;

Answer 2

To determine the deceleration of the car, we can use the equation of motion:

v^2 = u^2 + 2as

Where: - v is the final velocity (0 m/s, since the car comes to a stop) - u is the initial velocity (72 km/h, which needs to be converted to m/s) - a is the acceleration (negative, since the car is decelerating) - s is the distance traveled (unknown)

First, let's convert the initial velocity from km/h to m/s:

u = 72 km/h * (1000 m/1 km) * (1 h/3600 s) = 20 m/s

Now, we can rearrange the equation to solve for acceleration:

a = (v^2 - u^2) / (2s)

Since the car comes to a stop, the final velocity (v) is 0 m/s. Plugging in the values, we get:

0 = (0^2 - (20 m/s)^2) / (2s)

Simplifying the equation, we have:

0 = -400 m^2/s^2 / (2s)

Multiplying both sides by 2s, we get:

0 = -400 m^2/s^2

Since the coefficient of friction (μ) between the tires and the asphalt is given as 0.6, we can relate the acceleration to the coefficient of friction using the equation:

a = μg

Where: - a is the acceleration - μ is the coefficient of friction - g is the acceleration due to gravity (approximately 9.8 m/s^2)

Substituting the values, we have:

-400 m^2/s^2 = (0.6)(9.8 m/s^2)

Simplifying the equation, we get:

-400 m^2/s^2 = 5.88 m^2/s^2

Therefore, the deceleration of the car is approximately -5.88 m/s^2.

Please note that the negative sign indicates deceleration, which means the car is slowing down.