Question

Какое каличество теплоты потребуется для нагрева 10л волы от 20c до кипения? Удельная теплоемкость воды 4200 Дж(кг x C)При напряжении 2В сила тока в элтктрической цепи 0,5А.Найдите сопративление резистора.Электрический утюг рассчитан на напряжение 220в .Сопративление еге нагревательного элимента равно 88Ом.Определите энергию, потребляемую утюгом за 1800с.,и еге мощьность.По проводнику сопративлением 4 Ом в течение 2 мин прошло 500Кл электричества.Сколько теплоты выделил проводник?Найдите оптическую силу собирающей линзы ,если ее фокусное расстояние 4сммасса человека 90 кг,площадь его подошвы 60см в квадрате.Какое давление производит человек на пол?Вертолёт находится на высоте 200м .НАйдите его потенциальную энергию, если его масса 2тПомогите плиз

Answer 1

1)Q=po*V*c*(t2-t1)=1000*10*0,001*4200*(100-20)=3360000=3.36МДж

2)R=U/I=2B/0,5A=4Om

3)P=U*I=U^2/R=220*220/88=550Вт

А=P*t=550*1800=990 000Дж=990кДж

4)Q=i*R^2*t i=q/t=500/2*60=4,16A

Q=i*R^2*t=4,16*16*120=7987,2Om

6)p=F/S=F/2S=m*g/2S=90*10/2*60*10^-4=75 000Па=75кПа

7)E=mgh=2000kg*10m/c2*200m=4 000 000 Дж=4МДж

4)Д=1/F=1/8cm=1/0,08m=12,5дптр

Answer 2

ОПТИЧЕСКАЯ СИЛА РАВНА 

D=±1\F

D=±1\0.04=25

CОПРОТИВЛЕНИЕ НАХОДИМ ПО ЗАКОНУ ОМА I=U\R ОТСЮДА R=U\I=2\0.5=4 ОМ

1)Q=cmΔt=4200×10×80=3360кДж                   Δt=100-20=80

Answer 3

Calculation of Heat Required to Heat 10L of Water from 20°C to Boiling Point

To calculate the amount of heat required to heat 10L of water from 20°C to its boiling point, we need to use the formula:

Q = m * c * ΔT

Where: - Q is the heat energy required (in joules) - m is the mass of the water (in kilograms) - c is the specific heat capacity of water (in joules per kilogram per degree Celsius) - ΔT is the change in temperature (in degrees Celsius)

Given: - Volume of water (V) = 10L - Density of water (ρ) = 1kg/L (since the density of water is approximately 1kg/L) - Mass of water (m) = V * ρ = 10kg - Specific heat capacity of water (c) = 4200 J/(kg·°C) - Initial temperature (T1) = 20°C - Boiling point of water (T2) = 100°C

Using the formula, we can calculate the heat energy required:

Q = m * c * ΔT = 10kg * 4200 J/(kg·°C) * (100°C - 20°C)

Calculating the value:

Q = 10kg * 4200 J/(kg·°C) * 80°C = 3,360,000 J

Therefore, the amount of heat required to heat 10L of water from 20°C to its boiling point is 3,360,000 joules. [[1]]

Calculation of Resistance of a Resistor

To calculate the resistance of a resistor, we can use Ohm's Law:

V = I * R

Where: - V is the voltage (in volts) - I is the current (in amperes) - R is the resistance (in ohms)

Given: - Voltage (V) = 2V - Current (I) = 0.5A

Using Ohm's Law, we can rearrange the formula to solve for resistance:

R = V / I = 2V / 0.5A

Calculating the value:

R = 4 ohms

Therefore, the resistance of the resistor is 4 ohms. [[2]]

Calculation of Energy Consumed and Power of an Electric Iron

To calculate the energy consumed by an electric iron and its power, we can use the formulas:

Energy (E) = Power (P) * Time (t) Power (P) = Voltage (V)² / Resistance (R)

Given: - Voltage (V) = 220V - Resistance (R) = 88 ohms - Time (t) = 1800s

Using the power formula, we can calculate the power:

P = V² / R = (220V)² / 88 ohms

Calculating the value:

P = 550W

To calculate the energy consumed, we can use the energy formula:

E = P * t = 550W * 1800s

Calculating the value:

E = 990,000 joules

Therefore, the energy consumed by the electric iron in 1800 seconds is 990,000 joules and its power is 550 watts. [[3]]

Calculation of Heat Generated by a Conductor

To calculate the heat generated by a conductor, we can use the formula:

Q = I² * R * t

Where: - Q is the heat energy generated (in joules) - I is the current (in amperes) - R is the resistance (in ohms) - t is the time (in seconds)

Given: - Resistance (R) = 4 ohms - Time (t) = 2 minutes = 120 seconds - Electric charge (Q) = 500,000 coulombs (since 1 coulomb = 1 ampere * 1 second)

Using the formula, we can calculate the heat energy generated:

Q = I² * R * t = (500,000 coulombs)² * 4 ohms * 120 seconds

Calculating the value:

Q = 120,000,000,000 joules

Therefore, the heat generated by the conductor is 120,000,000,000 joules. [[4]]

Calculation of Optical Force of a Converging Lens

To calculate the optical force of a converging lens, we need to know the focal length of the lens and the mass and area of the object.

Given: - Focal length (f) = 4 cm - Mass of the person (m) = 90 kg - Area of the person's foot (A) = 60 cm²

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

F = m * g / A

Where: - m is the mass of the object (in kilograms) - g is the acceleration due to gravity (approximately 9.8 m/s²) - A is the area of the object (in square meters)

Converting the given values: - Focal length (f) = 0.04 m - Area of the person's foot (A) = 0.006 m²

Using the formula, we can calculate the optical force:

F = (90 kg * 9.8 m/s²) / 0.006 m²

Calculating the value:

F ≈ 147,000 N

Therefore, the optical force exerted by the converging lens is approximately 147,000 Newtons. [[5]]

Calculation of Potential Energy of a Helicopter

To calculate the potential energy of a helicopter, we need to know its mass and height.

Given: - Mass of the helicopter (m) = 2 tons = 2000 kg - Height (h) = 200 m

The potential energy (PE) can be calculated using the formula:

PE = m * g * h

Where: - m is the mass of the object (in kilograms) - g is the acceleration due to gravity (approximately 9.8 m/s²) - h is the height (in meters)

Using the formula, we can calculate the potential energy:

PE = 2000 kg * 9.8 m/s² * 200 m

Calculating the value:

PE = 3,920,000 joules

Therefore, the potential energy of the helicopter is 3,920,000 joules. [[6]]

I hope this helps! Let me know if you have any further questions.