Question

Лыжник спускается с горы со скоростью 0,5 м/с²,с начальной скоростью равной 0,за 20 секунд .С каким ускорением будет двигаться лыжник по горизонтальной поверхности после спуска с горы,если он остановится проехав 40 метров?Какова длина горы по которой спускается лыжник?

Answer 1

Уравнение движения с горы: x=0.5at^2; a=0.5 м/с^2, t1=20 с.
x=0.25*400=100 м. (длина спуска).
Скорость в конце горы равна v=at; v=0.5*20=10 м/с.
Уравнение движения после спуска: x=vt-0.5at^2;
40=10t2-0.5at2^2. где t2- время торможения после спуска.
Для скорости получим: v=at2; подставляем в уравнение движения
40=10t2-5t2;
40=5t2;
t2=8 с.
Получаем ускорение: a=v/t2; a=10/8=1.25 м/с^2

Answer 2

Calculating the Skier's Acceleration and Length of the Slope

To calculate the skier's acceleration and the length of the slope, we can use the kinematic equations of motion.

Given: - Initial velocity (u) = 0 m/s - Final velocity (v) = 0 m/s (since the skier stops) - Time taken (t) = 20 seconds - Distance traveled (s) = 40 meters

We can use the equation: v = u + at where: - v = final velocity - u = initial velocity - a = acceleration - t = time

Using this equation, we can find the acceleration (a) of the skier.

Calculating the Acceleration (a)

Using the equation v = u + at, we can solve for the acceleration (a): a = (v - u) / t

Substituting the given values: a = (0 - 0) / 20 a = 0 m/s²

So, the skier's acceleration on the horizontal surface after coming to a stop is 0 m/s².

Calculating the Length of the Slope

To find the length of the slope, we can use the equation: s = ut + (1/2)at² where: - s = distance traveled - u = initial velocity - t = time - a = acceleration

Using this equation, we can find the length of the slope.

Calculating the Length of the Slope (s)

Using the equation s = ut + (1/2)at², we can solve for the distance traveled (s): s = ut + (1/2)at² s = (0 * 20) + (1/2 * 0 * 20²) s = 0 + 0 s = 0 meters

Therefore, the length of the slope is 0 meters.

In summary, the skier's acceleration on the horizontal surface after coming to a stop is 0 m/s², and the length of the slope is 0 meters.