Question

За какое время работа тока в лампе сопротивлением 240 ом при токе 0,5 А сравняется с работой по подъёму груза в 2,4 т на высоту 100м?

Answer 1

Работа электрического тока равна:A=UIt

A2=Eп=mgh:

Найдем напряжение: U=I*R=240*0,5=120В

Приравниваем работы и получаем:

UIt=mgh;

t=mgh/UI=2400*9,8*100/120*0,5=39200с

Ответ: 39200 секунд

Answer 2

Calculation of Work in the Lamp

To calculate the work done in the lamp with a resistance of 240 ohms and a current of 0.5 A, we can use the formula:

Work (W) = Current (I) x Voltage (V) x Time (t)

Since the resistance (R) and current (I) are given, we can calculate the voltage (V) using Ohm's Law:

Voltage (V) = Current (I) x Resistance (R)

Let's calculate the voltage first:

Voltage (V) = 0.5 A x 240 ohms = 120 volts

Now, we can calculate the time (t) it takes for the work done in the lamp to be equal to the work done in lifting a 2.4-ton load to a height of 100 meters.

Calculation of Work in Lifting the Load

To calculate the work done in lifting the load, we can use the formula:

Work (W) = Force (F) x Distance (d)

The force (F) can be calculated using the formula:

Force (F) = Mass (m) x Acceleration due to gravity (g)

Given that the mass of the load is 2.4 tons and the acceleration due to gravity is approximately 9.8 m/s^2, we can calculate the force:

Force (F) = 2.4 tons x 9.8 m/s^2 = 23.52 kN

Now, we can calculate the work done in lifting the load:

Work (W) = Force (F) x Distance (d) = 23.52 kN x 100 m = 2352 kNm

Comparison of Work Done

To compare the work done in the lamp with the work done in lifting the load, we need to convert the units of work done in the lamp to the same unit as the work done in lifting the load.

1 kNm (kilonewton-meter) is equal to 1 kJ (kilojoule).

Converting the work done in the lamp to kilojoules:

Work (W) = 120 volts x 0.5 A x time (t)

Since we don't have the time (t) yet, we can't calculate the exact work done in the lamp. However, we can compare the work done in the lamp and the work done in lifting the load by comparing their units.

The work done in lifting the load is 2352 kNm, which is equal to 2352 kJ.

Therefore, the work done in the lamp will be equal to the work done in lifting the load when it reaches 2352 kJ.

Please note that without the exact time (t) for the work done in the lamp, we cannot provide a specific answer to when the work done in the lamp will be equal to the work done in lifting the load.