answer.
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
Llana [10]
2 years ago
10

The potential energy of a catapult was completely converted into kinetic energy by releasing a small stone with a mass of 20 gra

ms. The velocity of the stone when it reached the target was 15.0 meters/second. What was the value of the kinetic energy of the stone when it reached the target? A. 2.05 joules B. 2.25 joules C. 3.20 joules D. 4.43 joules
Chemistry
2 answers:
Blababa [14]2 years ago
4 0

Answer : The correct option is, 2.25 joules.

Explanation : Given,

Mass of the stone = 20 g

Velocity of the stone = 15 m/s

Formula used for kinetic energy is :

K.E=\frac{1}{2}mv^2

where,

K.E = kinetic energy of the stone

m = mass of the stone

v = velocity of the stone

Now put all the given values in this formula, we get the kinetic energy of the stone.

K.E=\frac{1}{2}\times (20g)\times (15m/s)^2

K.E=2250gm^2/s^2=2.25Kgm^2/s^2=2.25J

Therefore, The kinetic energy of the stone is, 2.25 joules.

vladimir1956 [14]2 years ago
3 0

1,000 grams = 1 kilogram

20 grams = 0.02 kilogram


Kinetic energy = (1/2) (mass) x (speed)²


                          (1/2) (0.02) x (15)² =


                                (0.01)  x  (225)  =  2.25 joules



You might be interested in
Ammonia gas is compressed from 21°C and 200 kPa to 1000 kPa in an adiabatic compressor with an efficiency of 0.82. Estimate the
Evgen [1.6K]

Explanation:

It is known that efficiency is denoted by \eta.

The given data is as follows.

     \eta = 0.82,       T_{1} = (21 + 273) K = 294 K

     P_{1} = 200 kPa,     P_{2} = 1000 kPa

Therefore, calculate the final temperature as follows.

         \eta = \frac{T_{2} - T_{1}}{T_{2}}    

         0.82 = \frac{T_{2} - 294 K}{T_{2}}    

          T_{2} = 1633 K

Final temperature in degree celsius = (1633 - 273)^{o}C

                                                            = 1360^{o}C

Now, we will calculate the entropy as follows.

       \Delta S = nC_{v} ln \frac{T_{2}}{T_{1}} + nR ln \frac{P_{1}}{P_{2}}

For 1 mole,  \Delta S = C_{v} ln \frac{T_{2}}{T_{1}} + R ln \frac{P_{1}}{P_{2}}

It is known that for NH_{3} the value of C_{v} = 0.028 kJ/mol.

Therefore, putting the given values into the above formula as follows.

     \Delta S = C_{v} ln \frac{T_{2}}{T_{1}} + R ln \frac{P_{1}}{P_{2}}

                = 0.028 kJ/mol \times ln \frac{1633}{294} + 8.314 \times 10^{-3} kJ \times ln \frac{200}{1000}

                = 0.0346 kJ/mol

or,             = 34.6 J/mol             (as 1 kJ = 1000 J)

Therefore, entropy change of ammonia is 34.6 J/mol.

3 0
2 years ago
You are writing a safety contract for your class. List 10 things you would include in the contract.
andre [41]

1.always listen to teacher

2 no eating in class

3 always have attentive listening

4 always have proper safety material

5 wear eyeglasses when needed

6 let others be able to listen

 sorry I could only think of 6

7 0
2 years ago
Read 2 more answers
Which of the following correctly describes a compound? (4 points)
wariber [46]

Explanation:

The atoms are chemically bonded together, and they retain their individual physical and chemical properties.

8 0
2 years ago
An unknown element X has the following isotopes: ⁵²X (89.00% abundant), ⁴⁹X (8.00% abundant), ⁵⁰X (3.00% abundant). What is the
Vlad [161]

Answer:

52 amu

Explanation:

To get the relative atomic mass of the element, we need to take into consideration, the atomic masses of the different isotopes and their relative abundances. We simply multiply the percentages with the masses. This can be obtained as follows:

[89/100 * 52] + [8/100 * 49] + [3/100 * 50]

46.28 + 3.92 + 1.5 =51.7 amu

The approximate atomic mass of element x is 52 amu

6 0
2 years ago
How many molecules are in 79g of fe2o3
horrorfan [7]
Convert grams —> mols and then mols —> atoms

We know that there are 6.02 x 10^23 atoms/mol

And we know that there are about 160 grams of fe2o3 per mol

So (79g fe2o3)/(160 g/mol) = .49 mol fe2o3

Now we use avogadro’s number to do

(.49 mol fe2o3)/(6.02 x 10^23 atoms/mol) = the answer.

I’ll leave the easy math to you.
7 0
2 years ago
Other questions:
  • What is the mass of 2.11 × 1024 sulfur atoms??
    14·1 answer
  • Witch of the following isotopes would most likely be unstable and therefore radioactive?
    14·1 answer
  • The highest energy occupied molecular orbital in the b−b bond of the b2 molecule is _____
    14·2 answers
  • When a 500. gram sample of water at 19.0oC absorbs 8.40 kiloJoules of heat, the temperature of the water will change to?
    11·1 answer
  • Which statement best describes the oxidation numbers of the atoms found in magnesium chloride?
    7·1 answer
  • Colorful fireworks often involve the decomposition of barium nitrate and potassium chlorate and the reaction of the metals magne
    9·1 answer
  • A piston containing 0.120moles of methane gas, CH4, has a volume of 2.12liters. If methane is added until the volume is increase
    6·1 answer
  • What is the pressure of a 3.00 L gas vessel that has 18.0 grams of helium at 25°C? (R= 0.0821 L atm/ mol K)
    7·1 answer
  • 1. What is the significance of understanding the characteristics of the earth? essay​
    8·1 answer
  • Calculate the molar mass of a 2.89 g gas at 346 ml, a temperature of 28.3 degrees Celsius, and a pressure of 760 mmHg.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!