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
vovangra [49]
3 years ago
5

PLS HELP ASAP!!! I don’t understand this at all

Physics
1 answer:
Mnenie [13.5K]3 years ago
7 0

Answer:

The part that completes the nuclear equation is:

           ^{221}_{87}Fr

Explanation:

<h2>A) Preliminar explanation</h2>

The <em>nuclear equation</em> represents a nuclear reaction: the change of the nucleus of an atom.

The given equation represents an actinium atom releasing an alpha particle.

This is the meaning of each part of the equation:

  • Ac is the chemical symbol of actinium
  • The superscript to the left of the chemical symbol is the mass number of the atom (number of protons plus number of neutrons). The mass number is 225.
  • The subscript to the left of the chemical symbol is the atomic number of the atom (number of protons). The atomic number is 89.

  • ^4_2He is the symbol of the alpha particle. It is an atom of helium
  • The mass number is 4
  • The atomic number is 2

<h2>B) Solution</h2>

To <em>complete the nuclear equation </em>you must do two balances: mass number balance and atomic number balance.

<u>i) Mass number balance</u>

  • 225 = A + 4 ⇒ A = 225 - 4 = 221

<u>ii) Atomic number balance</u>

  • 89 = Z + 2 ⇒ Z = 89 - 2 = 87

Therefore, the mass number of the unknown atom is 221, and the atomic number is 87.

From a periodic table, the element with atomic number 87 is francium, Fr.

Now, you have the chemical symbol, the atomic number, and the mass number of the unknown atom, which lets you to write the atom that completes the <em>nuclear equation</em>.

           ^{221}_{87}Fr

You might be interested in
A CAR ACCElerates FROM REST To
Ilia_Sergeevich [38]

Answer:

<u>666.6 kW</u>

Explanation:

<u>Power Formula</u>

  • Power = Force × Velocity

<u>Calculating Force</u>

  • F = ma
  • F = m(v - u / t) [From the equation v = u + at]
  • F = 2,000 (50/7.5)
  • F = 2,000 (20/3)
  • F = 40,000/3
  • F = 13333.3 N

<u>Solving for Power</u>

  • P = 13333.3 × 50
  • P = 666666.6 W
  • P = <u>666.6 kW</u>
5 0
2 years ago
During takeoff, an airplane climbs with a speed of 195 m/s at an angle of 15° above the horizontal. The speed and angle constitu
matrenka [14]

Answer:

The horizontal component of the velocity is 188 m/s

The vertical component of the velocity is 50 m/s.

Explanation:

Hi there!

Please, see the figure for a graphic description of the problem. Notice that the x-component of the vector velocity (vx), the y-component (vy) and the vector velocity form a right triangle. Then, we can use trigonometry to obtain the magnitude of vx and vy:

We can find vx using the following trigonometric rule of a right triangle:

cos α = adjacent / hypotenuse

cos 15° = vx / 195 m/s

195 m/s · cos 15° = vx

vx = 188 m/s

The horizontal component of the velocity is 188 m/s

To calculate the y-component we will use the following trigonometric rule:

sin α = opposite / hypotenuse

sin 15° = vy / 195 m/s

195 m/s · sin 15° = vy

vy = 50 m/s

The vertical component of the velocity is 50 m/s.

4 0
3 years ago
A 6.0-kilogram cart initially traveling at 4.0 meters per second east accelerates uniformly at 0.50 meter per second squared eas
VMariaS [17]

Answer: 5.5m/s

Explanation:

vf=vi+at

vf= 4.0m/s + (0.50m/s^2)(3.0s)

3 0
2 years ago
650 N boy and a 419 N girl sit on a 150 N porch swing that is 2.0 m long. If the swing is supported by a chain at each end, what
Sergio039 [100]

The tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.

<h3>Principle of moments</h3>

The Principle of Moments states that when a body is in equip, the sum of clockwise moment about a point is equal to the sum of anticlockwise moment about the same point.

The formula for calculating moment is given below:

  • Moment = Force × perpendicular distance from the pivot

<h3>Calculating the tension in the chains</h3>

From the principle of moments:

Let tension in chain 1 be T1 and tension in chain 2 be T2.

T1 + T2 = 150 + 650 + 419

T1 + T2 =1219

Taking all distances from chain 1,

Sum of Moments = 0

419 × 0.5 + 150 × 0.85 + 650 × 0.9 = T2 × 1.7

T2 = 922/17

T2 = 542.35 N

Then, T1 = 1219 - 542.35

T1 = 676.65 N

Therefore, the tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.

Learn more about tension and moments at: brainly.com/question/187404

brainly.com/question/14303536

7 0
2 years ago
Give reasons.<br>a) Sunlight does not fall on the ground where cloud forms shadow.​
Viefleur [7K]

Answer:

Sunlight passing through a cloud is scattered in various directions. Some photons eventually find their way out the bottom of the cloud, some are reflected upwards, and some are absorbed, serving to warm the cloud. Since only a fraction of the light makes it to ground level, you have a shadow.

Explanation:

Hope it helps you

4 0
3 years ago
Other questions:
  • An ideal air-filled parallel-plate capacitor has round plates and carries a fixed amount of equal but opposite charge on its pla
    7·1 answer
  • At a camp site there are tents of 2 shades. 1 made with black fabric and the other with white fabric. Which one will you prefer
    8·1 answer
  • Which compound is most likely a powerful and dangerous acid? H2S HBr Li2O LiBR
    13·2 answers
  • An electrically neutral balloon is rubbed on cloth and becomes positively charged. What can be said about its mass?
    10·2 answers
  • A box is pushed across a horizontal table at constant speed. Of the forces on it, which pair do we know are equal in magnitude b
    14·1 answer
  • A positively-charged object with a mass of 0.129 kg oscillates at the end of a spring, generating ELF (extremely low frequency)
    14·1 answer
  • In an automobile collision, a 44-kilogram passenger moving at 15 meters per second is brought to rest by an air bag during a 0.1
    5·1 answer
  • An airplane is flying at 635 km per hour at an altitude of 35,000 m. What is its velocity?
    13·1 answer
  • 10. Ron’s father finally installed cruise control on their flying car. He was having trouble because he kept of forgetting that
    10·1 answer
  • When drawing a free body diagram, which of the following things would NOT be included
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!