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
romanna [79]
3 years ago
12

The latent heat of fusion of alcohol is 50 kcal/kg and its melting point is -54oC. It has a specific heat of 0.60 in its liquid

state. Calculate the energy needed to melt 2.0 kg of solid alcohol at -54o and raise it to a temperature of -4°C.
40. kcal
100 kcal
160 kcal
280 kcal
Physics
1 answer:
sashaice [31]3 years ago
5 0

Answer:

C

Explanation:

To melt the alcohol

Heat needed = M . L  = 2 . 25  = 50 kcal

To warm up the alcohol

Heat needed = M . sp. ht. . ∆t   = 2 . 0.6 . 100  = 120 kcal

Total heat needed = 170 kcal

Assuming that 0.6 kcal/ kg / ˚C  is the specific heat and that the answer is wanted in kcal ( a rather odd unit to be in use here.)

You might be interested in
Two force vectors are oriented such that the angle between their directions is 38 degrees and they have the same magnitude. If t
Usimov [2.4K]

Answer:

Sum of the forces will be equal to 3.479 N

Explanation:

We have given two same forces are oriented at an angle of 38°

Magnitude of each force is given F_1=F_2=1.84

We have to find the sum of the forces

Sum of the forces will be equal to

F=\sqrt{F_1^2+F_2^2+2F_1F_2cos\Theta }

So sum of the forces will be equal to F=\sqrt{1.84^2+1.84^2+2\times 1.84\times 1.84\times cos38^{\circ} }=3.479

So sum of the force will be equal to 3.479 N

6 0
3 years ago
Why do people cover their flowers on a cool night. Think about radiation absorption conduction and temperature
Blababa [14]
When the temperature lowers the plants can freeze and die. One way to prevent that is to cover the plants so they dont freeze 

3 0
3 years ago
Philosophy: The Big Picture Unit 8
SVEN [57.7K]

D. Pragmatism applies to everyone, but utilitarianism is concerned with the upper class.
5 0
3 years ago
On February 15, 2013, Asteroid 2012 DA14 passed within 17,200 miles [mi] of the surface of the Earth at a relative speed of 7.8
xz_007 [3.2K]

Answer:

The total amount of energy that would have been released if the asteroid hit earth = The kinetic energy of the asteroid = 1.29 × 10¹⁵ J = 1.29 PetaJoules = 1.29 PJ

1 PJ = 10¹⁵ J

Explanation:

Kinetic energy = mv²/2

velocity of the asteroid is given as 7.8 km/s = 7800 m/s

To obtain the mass, we get it from the specific gravity and diameter information given.

Density = specific gravity × 1000 = 3 × 1000 = 3000 kg/m³

But density = mass/volume

So, mass = density × volume.

Taking the informed assumption that the asteroid is a sphere,

Volume = 4πr³/3

Diameter = 30 m, r = D/2 = 15 m

Volume = 4π(15)³/3 = 14137.2 m³

Mass of the asteroid = density × volume = 3000 × 14137.2 = 42411501 kg = 4.24 × 10⁷ kg

Kinetic energy of the asteroid = mv²/2 = (4.24 × 10⁷)(7800²)/2 = 1.29 × 10¹⁵ J

6 0
3 years ago
An object has an average acceleration of +6.18 m/s2 for 0.266 s . At the end of this time the object's velocity is +9.90 m/s .
Archy [21]

At the start of the 0.266 s, the object's speed was 8.26 m/s.

The question can only be talking about speed, not velocity.

4 0
3 years ago
Other questions:
  • A spherical balloon is filled with gas at a rate of 4 cm 3 /s . at what rate is the radius r changing with with respect to time
    5·1 answer
  • What does Newton’s law of universal gravitation say about the distance between objects?
    15·1 answer
  • Trigonometry Help, question posted below @AL2006
    14·1 answer
  • Calculate the acceleration of Josh riding his bicycle in a straight line that speeds up from 4 m/s to 6 m/s in 5 seconds
    13·2 answers
  • Isaac Newton used a ____ to break white light into its component colors.
    11·2 answers
  • Describe Lenz's law.
    11·1 answer
  • A motor is used to lift a 10 kg mass 2 m above the ground in 4 s. If the power input to the motor is 100 W. what is the efficien
    7·1 answer
  • A car's engine generates 100,000W of power as it exerts a force of 10,000N . How long does it take the car to travel 100m ?
    8·1 answer
  • The electricity received at an electrical substation has a potential difference of 20,000 V. What should the ratio of the turns
    12·1 answer
  • Which is one factor that contributes to the formation of polar, temperate, and tropical zones?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!