Question

Кран поднимает груз массой 2т. Чему равна работа, совершаемая краном за первые 5сек, если скорость поднятия равна 30м\мин?

Answer 1

За первые 5 секунд (1/12 мин) подняли груз на высоту 30*1/12м.
Совершенная работа=20000Н*30/12м =50 кДж

Answer 2

Calculation of Work Done by the Crane

To calculate the work done by the crane, we need to use the formula:

Work = Force × Distance

In this case, the force is equal to the weight of the load being lifted, and the distance is equal to the height the load is lifted.

Given: - Mass of the load = 2 tons = 2000 kg - Speed of lifting = 30 m/min - Time = 5 seconds

To calculate the distance, we need to convert the speed from meters per minute to meters per second. Since there are 60 seconds in a minute, we can divide the speed by 60 to get the speed in meters per second:

Speed = 30 m/min ÷ 60 = 0.5 m/s

Now, we can calculate the distance using the formula:

Distance = Speed × Time

Distance = 0.5 m/s × 5 s = 2.5 meters

Next, we can calculate the force using the formula:

Force = Mass × Acceleration due to gravity

The acceleration due to gravity is approximately 9.8 m/s².

Force = 2000 kg × 9.8 m/s² = 19600 N

Finally, we can calculate the work done by the crane using the formula:

Work = Force × Distance

Work = 19600 N × 2.5 m = 49000 Joules

Therefore, the work done by the crane in lifting a 2-ton load over a distance of 2.5 meters in the first 5 seconds is 49000 Joules.