Question

Двигатель подъемного крана имеет мощность 1.5 квт. сколько времени потребуется крану для поднятия бетонного блока массой 2 т на высоту 12 м?

Answer 1

T=Mgh/N
t=2000кг•9.8(10)•12/1500=16•9.8(10)≈160с

Answer 2

Calculation of Time Required to Lift a Concrete Block

To calculate the time required for a crane to lift a concrete block, we need to consider the power of the crane's engine and the mass and height of the block.

Given: - Power of the crane's engine: 1.5 kW - Mass of the concrete block: 2 tons (2000 kg) - Height to lift the block: 12 meters

To calculate the time required, we can use the formula:

Time = Work / Power

The work done to lift the block can be calculated using the formula:

Work = Force x Distance

The force required to lift the block can be calculated using the formula:

Force = Mass x Gravity

Where: - Mass is the mass of the block (2000 kg) - Gravity is the acceleration due to gravity (approximately 9.8 m/s^2)

Let's calculate the time required step by step.

1. Calculate the force required to lift the block: - Force = Mass x Gravity - Force = 2000 kg x 9.8 m/s^2

2. Calculate the work done to lift the block: - Work = Force x Distance - Work = (2000 kg x 9.8 m/s^2) x 12 m

3. Calculate the time required to lift the block: - Time = Work / Power - Time = [(2000 kg x 9.8 m/s^2) x 12 m] / 1.5 kW

Now, let's calculate the values.

Calculation:

1. Calculate the force required to lift the block: - Force = 2000 kg x 9.8 m/s^2 - Force = 19600 N

2. Calculate the work done to lift the block: - Work = (19600 N) x 12 m - Work = 235200 J (Joules)

3. Calculate the time required to lift the block: - Time = (235200 J) / 1500 W - Time = 156.8 seconds

Therefore, it will take approximately 156.8 seconds for the crane to lift the 2-ton concrete block to a height of 12 meters.

Please note that this calculation assumes ideal conditions and does not take into account factors such as friction, efficiency, and acceleration/deceleration time.