Heat is best defined as

How much heat is required to convert 500g of liquid water at 28°C into steam at 150°C? Take the specific heat capacity of water

JulijaS [17]

Answer:

1,327,063Joules

Explanation:

Heat energy is the energy needed to convert the state of a body from one phase to another.

According to the question, we want to calculate the total heat required to convert water into vapour (steam).

Note that before water can vapourize, it has to reach the boiling point first which is at 100°C. Heat energy needed to convert the water to 100°C is expressed as H1 = mcΔθ

m is the mass of the object in kg =0.5kg

c is the spcific heat capacity of water = 4183J/kg°C

Δθ is the change in temperature = 100-28 = 72°C

H1 = 0.5*4183*72

H1 = 150,588Joules

Energy required to convert the water to team H2 =mLsteam

Lsteam is the latent heat of vaporization = 2.26×10⁶J/kg

H2 = 0.5*2.26×10⁶

H2 = 1130000Joules

Heat energy needed to convert the water to 150°C is expressed as H3 = mcΔθ

m is the mass of the object in kg =0.5kg

c is the spcific heat capacity of steam= 1859J/kg°C

Δθ is the change in temperature = 150-100 = 50°C

H3 = 0.5*1859*50

H1 = 46,475Joules

Total Heat requires = H1+H2+H3 = 150,588Joules+1130000Joules+ 46,475Joules = 1,327,063Joules

8 0

3 years ago

A rotating fan completes 1200 revolutions every minute. consider the tip of a blade, at a radius of 0.19 m. through what distanc

ser-zykov [4K]

The tip of the fan moves through the outer side of the circle.

So it moves a distance of perimeter of circle in one revolution.

Perimeter of circle = 2 $\pi$ r, where r is the radius of circle.

In this case radius of circular motion = 0.19 meter

So perimeter of circle = 2 $\pi$ *0.19 = 0.38 $\pi$ = 1.194 m

So distance does the tip move in one revolution = 1.194 meter

5 0

3 years ago

What is the ratio of the intensities of an earthquake P wave passing through the Earth and detected at two points 14 km and 49 k

Molodets [167]

Answer:

$\dfrac{I_1}{I_2}=12.25$

Explanation:

$r_1$ = 14 km

$r_2$ = 49 km

Intensity of a wave is inversely proportional to distance

$I\propto \dfrac{1}{r^2}$

So,

$\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\Rightarrow \dfrac{I_1}{I_2}=\dfrac{49^2}{14^2}\\\Rightarrow \dfrac{I_1}{I_2}=12.25$

The ratio of the intensities is $\dfrac{I_1}{I_2}=12.25$

6 0

3 years ago

Name 2 common methods of polymerization.

navik [9.2K]

Answer: Addition polymerization & Condensation polymerization

6 0

3 years ago

Help!!

emmainna [20.7K]

Answer:

Mistakes, chaos theory.

Explanation:

Weather forecast refers to the application of technology and science in predicting what the condition's of an atmosphere would be at a particular time in a given location. Keyword here is "Predicting."

To accurately "predict" the weather, observation data needs to be collected from weather stations across the world. The data collected from the stations are too complex such that they can only be processed by supercomputers.

It is important to note that supercomputers used to predict weather are liable to make mistakes because the enormous challenge of weather forecasting is more than their capabilities.

In addition, there is a concept known as chaos theory. It explains how very small changes in initial weather conditions can change the final results. No thanks to chaos, meteorologists would not be able to predict weather accurately.

This is the reason why the world still suffers from the incidence of surprise rain, storms and other weather events that could be devastating.

4 0

3 years ago