Question

⦁ Вниз по наклонной плоскости с углом наклона к горизонту, равным 300, скользит тело. Какой путь пройдет тело за три секунды от начала скольжения, если коэффициент трения равен 0,2?

Answer 1

M*a=m*g*sina-k*m*g*cosa
a=g*(sina-k*cosa)=10*(0,5-0,2*0,87)=3,3 м/с2
S=a*t^2/2=3,3*9/2=14,9 м
Если ответ отличается, пересчитайте для g=9,8

Answer 2

The question is about the motion of a body sliding down an inclined plane with an angle of inclination to the horizon of 30 degrees and a coefficient of friction of 0.2. The answer is that the body will cover a distance of about 1.6 meters in three seconds from the start of sliding.

To find the answer, we need to use the following formula:

$$s = v_0t + \frac{at^2}{2}$$

where $s$ is the distance, $v_0$ is the initial velocity, $a$ is the acceleration, and $t$ is the time.

The initial velocity of the body is zero, since it starts from rest. The acceleration of the body is determined by the net force acting on it along the inclined plane, which is the difference between the component of the weight parallel to the plane and the friction force. The weight component is given by:

$$W_{\parallel} = mg\sin\alpha$$

where $m$ is the mass of the body, $g$ is the gravitational acceleration, and $\alpha$ is the angle of inclination. The friction force is given by:

$$F_f = \mu N$$

where $\mu$ is the coefficient of friction, and $N$ is the normal force. The normal force is equal to the component of the weight perpendicular to the plane, which is given by:

$$N = W_{\perp} = mg\cos\alpha$$

Therefore, the net force along the plane is:

$$F_{net} = W_{\parallel} - F_f = mg\sin\alpha - \mu mg\cos\alpha$$

The acceleration of the body is then:

$$a = \frac{F_{net}}{m} = g(\sin\alpha - \mu\cos\alpha)$$

Substituting the given values of $\alpha = 30^\circ$ and $\mu = 0.2$, we get:

$$a \approx 3.2 \text{ m/s}^2$$

Plugging this value into the formula for the distance, we get:

$$s = 0 + \frac{3.2t^2}{2}$$

For $t = 3$ seconds, we get:

$$s \approx 1.6 \text{ m}$$

This is the answer. You can find more information about this topic on the following web pages: [1](https://uchi.ru/otvety/questions/telo-skolzit-vniz-po-naklonoy-ploskosti-s-uglom-naklona-k-gorizontu-30-koeffitsient-treni), [2](https://online-otvet.ru/fizika/5cea71ff96f4e19a29f57675), [3](https://portal.tpu.ru/SHARED/s/SIB/Education/physics_1/Tab1/%D0%98%D0%94%D0%97_1.pdf). I hope this helps.