Question

Строитель за веревку поднимает ведро с бетонным раствором, прикладывая силу 250 Н. С какой скоростью он тянет веревку, если за 1 мин совершает работу 3 кДж?

Answer 1

1)A=N*t(где N-мощность)⇒N=A/t
N=F*V (где V-скорость)
2)A/t=F*V⇒V=A/(t*F)=3000/(60*250)=0.2(м/с)
Ответ:V=0.2 м/с

Answer 2

Calculating the Speed of Lifting the Bucket

To calculate the speed at which the builder is pulling the rope, we can use the work-energy principle, which states that the work done on an object is equal to the change in its kinetic energy.

The work done (W) can be calculated using the formula: W = F * d Where: - W = work done (in joules) - F = force applied (in newtons) - d = distance moved in the direction of the force (in meters)

Given that the builder completes 3 kJ of work in 1 minute, we can convert this to joules: 3 kJ = 3000 J

We also know the force applied by the builder: F = 250 N

Now, we can rearrange the work formula to solve for distance: d = W / F

Substituting the given values: d = 3000 J / 250 N d = 12 m

So, the distance moved by the builder in 1 minute is 12 meters.

To find the speed at which the builder is pulling the rope, we can use the formula: Speed = distance / time

Given that the distance moved is 12 meters in 1 minute, we can convert the time to seconds: 1 minute = 60 seconds

Substituting the values: Speed = 12 m / 60 s Speed = 0.2 m/s

Therefore, the builder is pulling the rope at a speed of 0.2 meters per second.