Question

на тело действует сила 2кн под углом 30. какую работу совершает сила трения , если тело движется с постоянной скоростью и перемещается на 10 м

Answer 1

А=Fhcosa
A= 2000*10*0.85=17кДЖ

Answer 2

Calculating the Work Done by Frictional Force

To calculate the work done by the frictional force when a force of 2 kN is applied at an angle of 30 degrees and the body moves a distance of 10 m at a constant velocity, we can use the following steps:

1. Calculate the Normal Force (N): - The normal force (N) can be calculated using the formula: N = mg, where m is the mass of the object and g is the acceleration due to gravity.

2. Determine the Frictional Force (F_r): - The frictional force (F_r) can be calculated using the formula: F_r = μN, where μ is the coefficient of friction and N is the normal force.

3. Calculate the Work Done by Frictional Force: - The work done by the frictional force can be calculated using the formula: W = F_r * d * cos(θ), where d is the distance moved and θ is the angle between the force and the direction of motion.

Calculation Steps

1. Calculate the Normal Force (N): - Given that the mass of the object is not provided, we'll assume a mass of 1 kg for the calculation. - Using the formula N = mg, where g is the acceleration due to gravity (approximately 9.81 m/s²), we can calculate N.

N = (1 kg) * (9.81 m/s²) = 9.81 N

2. Determine the Frictional Force (F_r): - The coefficient of friction (μ) is not provided, so we'll assume a value of 0.4 for this calculation. - Using the formula F_r = μN, we can calculate F_r.

F_r = (0.4) * (9.81 N) = 3.924 N

3. Calculate the Work Done by Frictional Force: - Using the formula W = F_r * d * cos(θ), where d = 10 m and θ = 30 degrees, we can calculate W.

W = (3.924 N) * (10 m) * cos(30°) ≈ 34.01 J

Conclusion

The work done by the frictional force when a force of 2 kN is applied at an angle of 30 degrees and the body moves a distance of 10 m at a constant velocity is approximately 34.01 joules.