Answer:
Espanol 7h2 that's c coupon
Answer:
The part that completes the nuclear equation is:

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.
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>.

Answer:
48.51ms / 174.6 km/h
Explanation:
y = 1/2 x g x t^2 v = g x t
when y = 120m
120 = 1/2 x 9.8 x t^2
t^2 = 24.49
t = 4.95s
when t = 4.95s
v = 9.8 x 4.95
v = 48.51 m/s = 174.6 km/h
I'd say its realistic. But I don't really know that sry
Answer:
Explanation:
a ) The direction of angular velocity vector of second hand will be along the line going into the plane of dial perpendicular to it.
b ) If the angular acceleration of a rigid body is zero, the angular velocity will remain constant.
c ) If another planet the same size as Earth were put into orbit around the Sun along with Earth the moment of inertia of the system will increase because the mass of the system increases. Moment of inertia depends upon mass and its distribution around the axis.
d ) Increasing the number of blades on a propeller increases the moment of inertia , because both mass and mass distribution around axis of rotation increases.
e ) It is not possible that a body has the same moment of inertia for all possible axes because a body can not remain symmetrical about all axes possible. Sphere has same moment of inertia about all axes passing through its centre.
f ) To maximize the moment of inertia of a flywheel while minimizing its weight, the shape and distribution of mass should be such that maximum mass of the body may be situated at far end of the body from axis of rotation . So flywheel must have thick outer boundaries and this should be
attached with axis with the help of thin rods .
g ) When the body is rotating at the same place , its translational kinetic energy is zero but its rotational energy can be increased
at the same place.