Question

Ученикам 10 класса вопрос по динамике На тело массой 0.8кг лежащей на горизонтальной поверхности действует сила 3.99 Н коэффициент трения 0.5 Найти ускорение тела.

Answer 1

Дано m=0,8 кг   Fтяг=3,99 Н    k=0,5     а- ?

проведем оценку   Fтр=k*m*g=0,5*0,8*9,8=3,92 Н

Fтяг>Fтр

ma=Fтяг-Fтр
а=(Fтяг-Fтр)/m=(3,99-3,92)/0.8=0.07/0,8=0.0875 м/с2

Answer 2

Problem Analysis

To find the acceleration of the object, we need to consider the forces acting on it. In this case, the force of friction and the applied force are the main forces to consider. We can use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration.

Solution

1. Given: - Mass of the object (m) = 0.8 kg - Applied force (F) = 3.99 N - Coefficient of friction (μ) = 0.5

2. Calculate the force of friction (Ff) using the formula: ``` Ff = μ * N ``` where N is the normal force. Since the object is on a horizontal surface, the normal force is equal to the weight of the object (mg). ``` N = mg ``` Substituting the values: ``` N = 0.8 kg * 9.8 m/s^2 ``` ``` Ff = 0.5 * (0.8 kg * 9.8 m/s^2) ```

3. Calculate the net force (Fnet) acting on the object: ``` Fnet = F - Ff ```

4. Use Newton's second law to find the acceleration (a): ``` Fnet = ma ```

5. Substitute the values and solve for acceleration (a).

Calculation

Let's calculate the acceleration using the given values:

1. Calculate the force of friction (Ff): ``` N = 0.8 kg * 9.8 m/s^2 = 7.84 N ``` ``` Ff = 0.5 * 7.84 N = 3.92 N ```

2. Calculate the net force (Fnet): ``` Fnet = 3.99 N - 3.92 N = 0.07 N ```

3. Use Newton's second law to find the acceleration (a): ``` Fnet = ma ``` ``` 0.07 N = 0.8 kg * a ```

4. Solve for acceleration (a): ``` a = 0.07 N / 0.8 kg = 0.0875 m/s^2 ```

Answer

The acceleration of the object is 0.0875 m/s^2.

Please let me know if you need any further clarification.