The answer to the question above is "630.25 hours" which is the time to recoup the difference in the water heater cost. This problem can be solved using a simple algebra equation which stated as (18*115*0.1/1000)x - (4*220*0.1/1000)x = $75. In this formula, x represents the time to recoup the difference in the water heater cost (Calculation: 0.207x-0.088x=75 --> 0.119x = 75 --> x = 630.25)<span>. </span>
Mass, m = 4g = 0.004 kg
Velocity, = 50cm/s = 0.5m/s
Distance, 10cm = 0.1m
The wall would have to resist the energy acquired by the bullet.
Kenetic Energy of bullet = Resistance offered by the wall.
1/2 mv² = Resistance Force * Distance
(1/2) * 0.04 * 0.5 * 0.5 = F * 0.1
0.5 * 0.04 * 0.5 * 0.5 = F * 0.1
0.5 * 0.04 * 0.5 * 0.5/0.1 = F
0.05 = F
Therefore, Resistance offered by the wall = 0.05 N
Turn into stone. this will cause erosion for magma to turn to stone
We have vector 
Therefore,
x component = 17.9 * cos80 degree = 3.108
y component = 17.9 * sin80 degrees = 17.628
<h3>What is a vector?</h3>
An object with both magnitude and direction is referred to be a vector. A vector can be visualized geometrically as a directed line segment, with an arrow pointing in the direction and a length equal to the magnitude of the vector. The vector points in a direction from its tail to its head.
If the magnitude and direction of two vectors match, they are the same vector. This shows that if we move a vector to a different location without rotating it, the final vector will be the same as the initial vector. The vectors that denote force and velocity are two examples. The direction of force and velocity are both fixed. The size of the vector would represent the force's strength or the velocity's corresponding speed.
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