Question

Автомобиль с двумя ведущими осями под действием силы тяги 800 Н на некотором отрезке горизонтального пути увеличил скорость с 36 км/ч до 72 км/ч. Определить время, за которое произошло изменение скорости, и путь, пройденный за это время. Масса автомобиля 1200 кг.

Answer 1

По закону сохранения энергии:
$\frac{m*v_{1} ^{2_} }{2}$ +F(тяги) *S=$\frac{m*v_{2} ^{2_} }{2}$
Из этого уравнения находим S(путь);
$\left \{ {{s= v_{0}t+a t^{2}/2 } \atop {v= v_{0} +at }} \right.$
Из этой системы уравнений находим t

Answer 2

Given Information:

- Force of traction: 800 N - Initial speed: 36 km/h - Final speed: 72 km/h - Mass of the car: 1200 kg

Calculating Time:

To determine the time it took for the change in speed to occur, we can use the formula:

Change in speed = (Final speed - Initial speed)

Converting the speeds from km/h to m/s:

Initial speed = 36 km/h = (36 * 1000) / 3600 m/s = 10 m/s

Final speed = 72 km/h = (72 * 1000) / 3600 m/s = 20 m/s

Substituting the values into the formula:

Change in speed = (20 m/s - 10 m/s) = 10 m/s

Next, we can use the formula:

Force = (Mass * Change in speed) / Time

Rearranging the formula to solve for time:

Time = (Mass * Change in speed) / Force

Substituting the given values:

Time = (1200 kg * 10 m/s) / 800 N = 15 seconds

Therefore, it took 15 seconds for the change in speed to occur.

Calculating Distance:

To determine the distance traveled during this time, we can use the formula:

Distance = Initial speed * Time + (1/2) * (Change in speed) * Time

Substituting the given values:

Distance = 10 m/s * 15 s + (1/2) * 10 m/s * (15 s) = 150 m + 75 m = 225 m

Therefore, the car traveled a distance of 225 meters during this time.