1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Nookie1986 [14]
3 years ago
12

What minimum heat is needed to bring 250 g of water at 20 ∘C to the boiling point and completely boil it away? The specific heat

of water is 4190 J/(kg⋅K) and its heat of vaporization is 22.6×105 J/kg.
Physics
1 answer:
Amiraneli [1.4K]3 years ago
4 0

Answer:633.8 KJ

Explanation:

Given

mass of water\left ( m\right )=250gm

Initial temperature\left ( T_i\right )=20^{\circ}C

Final temperature \left ( T_f\right )=100^{\circ}C

Specific heat of water \left ( c \right )=4190 J/kg-k

heat of vaporization\left ( L\right )=22.6\times 10^5 J/kg

Heat required for process\left ( Q\right )=heat to raise water temperature from 20 to 100 +Heat to vapourize water completely

Q=mc\left ( T_f-T_i\right )+mL

Q=0.25\times 4190\times \left ( 100-20\right )+0.25\times 22\times 10^5

Q=\left ( 0.838+5.5\right )\times 10^5

Q=6.338\times 10^5J=633.8 KJ

You might be interested in
Q 1 . How many significant figures are in the following measurement? 0.0009(1 point)
Crazy boy [7]

Here we have some questions about experimental errors.

Q1) We want to see how many significant figures have the measure:

0.0009

The number of significant figures is the number of known digits that are not the leading zeros.

Here we can see four leading zeros, and a single-digit different than zero, which is a 9.

Then we have only one significant figure, the 9.

Q2) Here we will use the measure that is the less exact, as the error of that measure may be larger than the smaller significant figures of the other measures.

Then:

31.2 lb + 38.02lb + 45 lb

The worst measure is 45lb, so the smallest significant figure that we should use is the first one at the left of the decimal point, then we need to round the other two measures to the next whole number, we will get:

31 lb + 38 lb + 45 lb = 114lbs

Q3) We know that the measure is 11.5 seconds and the uncertainty of 1.7%, then the uncertainty will be the 1.7% of the above measure:

(1.7%/100%)*11.5 s = 0.1955 s

Notice that our measure has one significant figure after the decimal point, so we need to round the error to the same significant figure.

0.1955 s ≈ 0.2s

Then the measure is:

11.5 s ± 0.20 s

Q4) We have the measure:

312.0 mph ± 3.9 mph.

The percent uncertainty will be the quotient between the error and the measure times 100%, or:

(3.9 mph/312.0 mph)*100%  = 1.25%

This is a percent error, we do not need to round this.

If you want to learn more, you can read:

brainly.com/question/17339020

5 0
2 years ago
local AM radio station broadcasts at a frequency of 685.9 kHz. Calculate the wavelength at which they are broadcasting. Waveleng
natta225 [31]

Answer:

λ = 437 m.

Explanation:

  • Since a radio wave is a electromagnetic type of wave, it propagates approximately at the same speed of light in vacuum, 3*10⁸ m/s.
  • As in any wave, there exist a fixed relationship between the propagation speed, the wavelength and the frequency of the radio wave, as follows:

       c = \lambda* f (1)

  • Replacing by the values of the speed and the frequency, and solving for the wavelength λ, we get:

       \lambda = \frac{c}{f} =\frac{3e8 m/s}{685.9e31/s} =437 m  (2)

8 0
2 years ago
You add 50 mL of water at 20C to 200 mL of water at 70C. What is the most likely final temperature of the mixture?
Veseljchak [2.6K]
100*20 + 200*80 = 300* T
T = 60
5 0
3 years ago
Read 2 more answers
What principle is responsible for alternating light and dark bands when light passes through two or more narrow slits? What prin
kipiarov [429]

Answer:

Interference

Explanation:

When two waves of same frequency and constant phase difference super impose at a point on the screen then due to their superposition we will get different intensity of light at different positions of the screen

This phenomenon of redistribution of energy is known as interference of light.

So at the position of screen where the light intensity is maximum on the screen is known as constructive interference while the positions on the screen where it will get minimum intensity on the screen is known as destructive interference of the light

So correct answer would be

Interference

4 0
3 years ago
two bumper cars collide into each other and each caor jolts backwards what law is this isnt it newtons second law?
Yanka [14]
Yes because the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
5 0
3 years ago
Other questions:
  • Darryl throws a basketball at the gym floor. The ball bounces once on the floor and comes to rest in his coach’s hands. At which
    6·1 answer
  • Calculate the final temperature of a mixture of 0.350 kg of ice initially at 218°C and 237 g of water initially at 100.0°C.
    6·1 answer
  • A mass of 10 kg is at a point A on the table. It moved to a point B. If the line joining A and B is horizontal. What is the work
    12·1 answer
  • imagine you are working as a rollercoaster designer. you are building a ride the top speed of a 65m/s at the bottom of the first
    14·1 answer
  • I have a 3 cc piece of aluminum with a density of steel with a mass of 24.0 g. I cut it into 2 equal pieces. How has the density
    13·1 answer
  • Pls help i’ll give brainliest if you give a correct answer!!
    14·2 answers
  • The addition of electron shells results in _____
    14·1 answer
  • Elements in compounds are held together by chemical what
    9·1 answer
  • The state of a medium affect the speed of sound
    11·1 answer
  • A 150 g sample of brass at 100 °C is placed in a Styrofoam cup of water containing 120 mL of water at 10 °C. No heat is lost to
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!