Answer:
It will take 313.376 sec to raise temperature to boiling point
Explanation:
We have given that potential difference V = 120 Volt
Current i = 4.50 A
So resistance 
Heat flow in resistor will be equal to 
It is given that this heat is used for boiling the water
Mass of the water = 0.525 kg = 525 gram
Specific heat of water 4.186 J/gram/°C
Initial temperature is given as 23°C
Boiling temperature of water = 100°C
So change in temperature = 100-23 = 77°C
Heat required to raise the temperature of water 
So 
t = 313.376 sec
So it will take 313.376 sec to raise temperature to boiling point
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:
See the answers below.
Explanation:
We can solve both problems using Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F =m*a
where:
F = force [N] (units of newtons)
m = mass = 1000 [kg]
a = acceleration = 3 [m/s²]
![F = 1000*3\\F=3000[N]](https://tex.z-dn.net/?f=F%20%3D%201000%2A3%5C%5CF%3D3000%5BN%5D)
And the weight of any body can be calculated by means of the mass product by gravitational acceleration.
![W=m*g\\W=1000*9.81\\W=9810 [N]](https://tex.z-dn.net/?f=W%3Dm%2Ag%5C%5CW%3D1000%2A9.81%5C%5CW%3D9810%20%5BN%5D)
1.5 m/s is the velocity.
9.3 m is the length of aisle, over which Distance will be covered.
Time is demanded in which the child will move the cart over the aisle with 1.5 m/s.
v=S/t
and,
t=S/v
Put values,
t=9.3/1.5=6.2 s
Answer B. 112 m
Step-by-Step Explanation
initial velocity u = 20 m /s
final velocity v = 36 m /s
time taken t = 4 s
acceleration = (v - U) / t
= (36 - 20) / 4
a=4m/s2
from the formula
7-u2=2as , sis distance covered
putting the values
362-202=2×4×s
1296 - 400 = 8 x S
S= 112 m