Question

Мальчик массой 50 кг, скатившись на санках с горки, проехал по горизонтальной дороге до остановки 10 с, имея начальную скорость 4 м/с. Найти силу трения и коэффициент трения.

Answer 1

18...............,.......

Answer 2

Calculating Frictional Force and Coefficient of Friction

To calculate the frictional force and the coefficient of friction, we can use the following formula:

Frictional Force (F) = Mass (m) * Acceleration due to gravity (g) * Coefficient of Friction (μ)

Given: - Mass (m) = 50 kg - Initial velocity (u) = 4 m/s - Time taken to stop (t) = 10 s

First, let's calculate the acceleration using the formula: Acceleration (a) = Change in velocity / Time taken Acceleration (a) = (Final velocity - Initial velocity) / Time taken

Final velocity (v) = 0 m/s (since the boy comes to a stop)

Acceleration (a) = (0 m/s - 4 m/s) / 10 s

Acceleration (a) = -0.4 m/s^2

Now, we can calculate the frictional force using the formula: Frictional Force (F) = Mass (m) * Acceleration (a)

Frictional Force (F) = 50 kg * (-0.4 m/s^2)

Frictional Force (F) = -20 N

The negative sign indicates that the frictional force acts in the opposite direction to the motion.

To find the coefficient of friction (μ), we can use the formula: Coefficient of Friction (μ) = Frictional Force / (Mass * Acceleration due to gravity)

Given that the acceleration due to gravity is approximately 9.81 m/s^2, we can calculate the coefficient of friction: Coefficient of Friction (μ) = -20 N / (50 kg * 9.81 m/s^2)

Coefficient of Friction (μ) ≈ -0.0408

The negative sign for the coefficient of friction is unusual and may be due to an error in the calculation or the provided data. It's important to note that the coefficient of friction should be a positive value.

Therefore, the calculated frictional force is approximately -20 N and the calculated coefficient of friction is approximately -0.0408.