Question

ПОМОГИТЕ!!! При равномерном движении вверх сила натяжения троса, привязанного к грузу, 270 Н; при равномерном опускании этого груза - сила натяжения 250 Н. определить массу груза и силу сопротивления при его движении

Answer 1

Вверх:

T - mg - F= 0

T = F + mg

Вниз:

T = mg ; m = T/g = 250/10 = 25кг.

270 = F + 250 ; F = 270 - 250 = 20H.

Answer 2

Calculation of the Mass of the Load and the Resistance Force

To determine the mass of the load and the resistance force during its motion, we can use the equations of motion and the concept of tension in the rope.

Let's denote the mass of the load as m and the resistance force as R.

When the load is moving upwards with uniform motion, the tension in the rope is 270 N. According to Newton's second law, the net force acting on the load is equal to the product of its mass and acceleration. Since the load is moving upwards with uniform motion, the net force is equal to the tension in the rope minus the force of gravity acting on the load:

Tension - Force of Gravity = m * acceleration

The force of gravity acting on the load can be calculated using the equation:

Force of Gravity = m * g

where g is the acceleration due to gravity (approximately 9.8 m/s^2).

Substituting the force of gravity into the first equation, we have:

Tension - m * g = m * acceleration

Similarly, when the load is moving downwards with uniform motion, the tension in the rope is 250 N. The equation becomes:

Tension - m * g = -m * acceleration (negative sign indicates downward motion)

Now we have two equations with two unknowns (mass and acceleration). By solving these equations simultaneously, we can find the values of m and acceleration.

Solution:

Let's solve the equations to find the mass of the load and the acceleration.

Equation 1: 270 N - m * g = m * acceleration Equation 2: 250 N - m * g = -m * acceleration To eliminate the acceleration, we can add the two equations:

270 N - m * g + 250 N - m * g = m * acceleration - m * acceleration

Simplifying the equation:

520 N - 2m * g = 0

Now we can solve for m:

2m * g = 520 N

m = 520 N / (2 * g)

Using the value of acceleration due to gravity g ≈ 9.8 m/s^2, we can calculate the mass of the load:

m ≈ 26.53 kg

To find the resistance force, we can substitute the calculated mass into either Equation 1 or Equation 2 and solve for the resistance force. Let's use Equation 1:

270 N - m * g = m * acceleration

Substituting the values:

270 N - 26.53 kg * 9.8 m/s^2 = 26.53 kg * acceleration

Simplifying the equation:

acceleration ≈ 0 m/s^2

Since the load is moving with uniform motion, the acceleration is approximately zero. Therefore, the resistance force can be calculated as:

R = m * g ≈ 26.53 kg * 9.8 m/s^2 ≈ 259.59 N

Answer:

The mass of the load is approximately 26.53 kg and the resistance force during its motion is approximately 259.59 N.