Answer:
<em>The distance covered by comet is </em>
Explanation:
Speed is defined as the rate of change of distance with time. It is given by the equation speed= 
Thus distance= 
In this problem it is given that speed of comet= 
time travelled by the comet= 4 hours
Thus distance= 
= 
= 
For this case we have that by definition, the kinetic energy is given by the following formula:

Where:
m: It is the mass
v: It is the velocity
According to the data we have to:

Substituting the values we have:

finally, the kinetic energy is 
Answer:
Option A
The mass of an object always stays the same since it is really just the amount of matter in an object so no matter the force applied, as long as the object does not lose or gain matter, the object stays the same
Explanation:
The given data is as follows.
Resistance (R) = 1200 ohm, Area (A) =
m (as
)
Diameter (d) = 2.3 mm =
m
First, we will calculate the length as follows.
R =
Here,
= resistivity of aluminium = 
Putting the given values above and we will calculate the value of length as follows.
R =
1200 = 
L = 
As the circumference of circular wire = 
or, =
= 
And, number of turns will be calculated as follows.
No. of turns × Circumference = Length of wire
No. of turns × 
= 
Thus, we can conclude that
turns of wire are needed.
Answer:

Explanation:
The original equation is:

We notice that:
- we have 1 atom of Fe on the left, and 2 atoms of Fe on the right
- we have 2 atoms of O on the left, and 3 atoms of O on the right
Therefore, the equation is not balanced.
In order to balance it, we can add:
- a coefficient 3 in front of 
- a coefficient 2 in front of 
So we have:

Now the oxygen is balanced, but the iron it not balanced yet, since we have 1 Fe on the left and 4 on the right. Therefore, we should add a coefficient 4 on the Fe on the left:
