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
Serga [27]
3 years ago
7

1. You wish to heat 20 kg of water from 40°C to 80°C. How many kcal of heat are necessary to do this? To how many kJ does this c

orrespond?​
Physics
1 answer:
adelina 88 [10]3 years ago
8 0

Answer:

<h2>3,343.68kJ </h2>

Explanation:

Heat energy used up can be calculated using the formula:

H = mcΔt

m = mass oof the object (in kg) = 20kg

c = specific heat capacity of water = 4179.6J/kg°C

Δt change in temperature = 80-40 = 40°C

H= 20* 4179.6 * 40

H = 3,343,680Joules

H = 3,343.68kJ

You might be interested in
NO LINKS: Which of the following best demonstrates Newton's Third Law?
irina1246 [14]

The best demonstration that applies to Newton's Third Law of motion would be D) When you walk your foot pushes down on the ground while the ground pushes back on your foot.

------------------

Newton's Third Law states that for every action, there is an equal and opposite reaction. This is actually explains that forces come in pairs and forces are an interaction between two objects. As per the correct option given in the question explains Newton’s Third Law.  

------------------

When you walk your foot (say object A) pushes down on the ground while the ground (say object Q) pushes back on your foot with the same force but in the opposite direction.

7 0
2 years ago
Which object has the HIGHEST mass?
Arte-miy333 [17]
I think it would be A: gold ring

if you were to place all of these on a bed of water, the ring would be the first to sink.
5 0
2 years ago
Carlos was camping and getting cold as the sun went down. He wanted to light a fire for warmth and light. However, he discovered
storchak [24]
1. The chemical reaction produced by Carlo's fire is exergonic because energy is "going out". As the reaction proceeds, entropy increases as the energy stored in the dry wood and leaves are used up as fuel to create the fire which produces low quality light and warmth.  

2. This reaction is a classic example of an exothermic reaction. Exothermic reactions are characterized with the presence of heat and light in the products. Combustion reactions are always exothermic in nature.

3. Catalyst are substances that are used to speed up reactions by lowering the activation requirement. Catalysts aren't consumed in the reaction and can still be chemically retrieved afterwards. In this situation, the leaves cannot be retrieved after the reaction ends. The leaves speed up the heating of the wood but it does not behave as a catalyst. 
6 0
3 years ago
Question 2 of 10
Arlecino [84]

Answer:

B: Energy that is transformed is neither created or destroyed

Explanation:

4 0
2 years ago
A research vessel is mapping the bottom of the ocean using sonar. It emits a short sound pulse called "ping" downward. The frequ
Elena L [17]

Answer:

The ocean is 6485.6m deep when measured from the vessel

Explanation:

v=1474m/s

t=8.88s

let d represent distance from the vessel to the ocean bottom.

an echo travels a distance equivalent to 2d, that is to and fro after it reflects from the obstacle.

velocity=\frac{distance}{time}\\ v=\frac{2d}{t} \\vt=2d\\d=\frac{vt}{2}

d=\frac{1474*8.8}{2}

d= 6485.6m

7 0
2 years ago
Other questions:
  • Why do stretching exercises increase flexibility more than cardio exercises?
    11·1 answer
  • A steel wire, 3.2 m long, has a diameter of 1.2 mm. The wire stretches 1.6 mm when it bears a load. Young's modulus for steel is
    10·1 answer
  • In which of the following cases is work being done on an object? Question 2 options: Pushing against a locked door Carrying a bo
    12·1 answer
  • Which statement best defines inertia?
    14·2 answers
  • 2. In a famous letter to Robert Hooke, Isaac Newton wrote, "If I have seen further it is only by standing on the shoulders of gi
    12·1 answer
  • Solve 13.004+3.09+112.947
    9·1 answer
  • In an inertia balance, a body supported against gravity executes simple harmonic oscillations in a horizontal plane under the ac
    12·1 answer
  • What form of energy transforms to what other form when you turn on a steam iron?
    5·2 answers
  • National Instant Criminal Background Check System is used for a person trying to access a government website.
    7·1 answer
  • A golden-colored cube is handed to you. The person wants you to buy it for $100, saying that is a gold nugget. You pull out your
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!