Question

Трамвай, двигавшийся со скоростью v = 18 км/ч, начал экстренное торможение, при этом его колёса оказались полностью заблокированными и перестали вращаться. Определите тормозной путь трамвая, если коэффициент трения колёс по рельсам k = 0,15.

Answer 1

Ответ:

250м

Объяснение: я не уверена то что так, ну ладно

Answer 2

Calculation of Braking Distance

To calculate the braking distance of the tram, we can use the following formula:

Braking Distance = (Initial Velocity^2) / (2 * Deceleration)

In this case, the initial velocity of the tram is 18 km/h, which needs to be converted to m/s. The coefficient of friction between the wheels and the rails is given as 0.15.

Let's calculate the braking distance step by step:

1. Convert the initial velocity from km/h to m/s: - 1 km/h = 0.2778 m/s - Initial Velocity = 18 km/h * 0.2778 m/s = 5 m/s

2. Calculate the deceleration using the coefficient of friction: - Deceleration = k * g - k = coefficient of friction = 0.15 - g = acceleration due to gravity = 9.8 m/s^2 (approximate value) - Deceleration = 0.15 * 9.8 m/s^2 = 1.47 m/s^2

3. Substitute the values into the formula to calculate the braking distance: - Braking Distance = (Initial Velocity^2) / (2 * Deceleration) - Braking Distance = (5 m/s)^2 / (2 * 1.47 m/s^2) - Braking Distance = 25 m^2/s^2 / 2.94 m/s^2 - Braking Distance ≈ 8.5 meters

Therefore, the braking distance of the tram, when its wheels are completely locked and not rotating, is approximately 8.5 meters.