Question

Тело массой 1кг движется по горизонтальной плоскости. на тело действует сила F=10Н под углом 30 градусов к горизонту. коэффициент трения между телом и плоскостью равен 0,4. чему равен модуль силы трения, действующий на тело?

Answer 1

Дано:
m = 1 кг.
F = 10 Н
α = 30°
μ - 0.4
Найти: Fтр - ?

Решение: 
Fт = F × cos 30° ; cos 30° √3/2 ; Fт = 10 × √3/2 = 5√3 (H)

N = F × sin30°
sin 30° = 1/2
N = 0.5 (Н) 

Fтр =  0.4 × (5 + mg)  = 0.4 × (5+9.8)  = 5.92 (H)

Ответ: 5.92 (H)

Answer 2

Calculation of the Frictional Force

To calculate the magnitude of the frictional force acting on the body, we need to consider the force applied to the body, the angle at which it is applied, and the coefficient of friction between the body and the surface it is moving on.

Given: - Mass of the body (m) = 1 kg - Applied force (F) = 10 N - Angle of the applied force (θ) = 30 degrees - Coefficient of friction (μ) = 0.4

To find the frictional force, we can break down the applied force into its horizontal and vertical components. The vertical component does not affect the frictional force, so we will focus on the horizontal component.

The horizontal component of the applied force can be calculated using the formula:

F_horizontal = F * cos(θ)

Substituting the given values:

F_horizontal = 10 N * cos(30 degrees) = 10 N * 0.866 = 8.66 N

Now, we can calculate the frictional force using the formula:

Frictional force (F_friction) = μ * Normal force

The normal force is the force exerted by the surface on the body perpendicular to the surface. In this case, it is equal to the weight of the body, which can be calculated using:

Normal force = mass * gravitational acceleration

Substituting the given values:

Normal force = 1 kg * 9.8 m/s^2 = 9.8 N

Finally, substituting the values of the coefficient of friction and the normal force into the formula for frictional force:

F_friction = 0.4 * 9.8 N = 3.92 N

Therefore, the magnitude of the frictional force acting on the body is 3.92 N.