Question

Подъёмный кран мощностью 2 кВт поднял груз массой 240 кг за время 12с.На какую высоту был при этом поднят груз? НУЖНО ОЧЕНЬ!!!СРОЧНО!!

Answer 1

Р=2 кВт=2000 Вт
m=240 кг
t=12с
h-? 
mgh=Pt, h=Pt/(mg)=2000*12/2400= 10 м.

Answer 2

Calculation of the Height

To calculate the height to which the load was lifted by the crane, we can use the formula:

Work = Force x Distance

In this case, the work done by the crane is equal to the gravitational potential energy gained by the load. The formula for gravitational potential energy is:

Potential Energy = Mass x Gravity x Height

Since the work done by the crane is equal to the potential energy gained by the load, we can equate the two formulas:

Force x Distance = Mass x Gravity x Height

Given that the power of the crane is 2 kW (or 2000 W) and the time taken to lift the load is 12 seconds, we can calculate the force exerted by the crane using the formula:

Work = Power x Time

Substituting the given values:

Force x Distance = Power x Time

Force = (Power x Time) / Distance

Now, we can substitute the force into the equation for potential energy:

(Power x Time) / Distance x Distance = Mass x Gravity x Height

Simplifying the equation:

Height = (Power x Time x Mass x Gravity) / (Force x Distance)

Given that the power of the crane is 2 kW (or 2000 W), the time taken to lift the load is 12 seconds, the mass of the load is 240 kg, the acceleration due to gravity is approximately 9.8 m/s^2, and the force exerted by the crane is calculated as mentioned above, we can calculate the height to which the load was lifted.

Let's calculate the height using the given values.