Answer:
A
Explanation:
a statement that can be tested through the scientific method
<span>The outermost energy level of an element are called the valence shell, that holds the valence electrons. they consist of the highest energy level. In aluminum, the valence electrons are 3. </span>
Substract two consecutive terms of the sequence to see if there is a common difference:

As we can see, there is a common difference of -6.
Then, if a number of the sequence is given, the next one can be found by adding -6 (which is the same as subtracting 6).
Notice that the first term of the sequence is 3.
Then, the rule for the sequence is to start with 3 and add -6 repeatedly.
Therefore, the correct choice is option A) Start with 3 and add -6 repeatedly.
Answer:
0.78 m
Explanation:
The relationship between wavelength and frequency of a wave is given by

where
v is the speed of the wave
f is the frequency
is the wavelength
For the sound wave in this problem, we have
is the frequency
v = 344 m/s is the speed of sound in air
Substituting into the equation and re-arranging it, we find the wavelength:

Answer: K.E = 0.4 J
Explanation:
Given that:
M = 1.0 kg
h = 0.04 m
K.E = ?
According to conservative of energy
K.E = P.E
K.E = mgh
K.E = 1 × 9.81 × 0.04
K.E = 0.3924 Joule
The kinetic energy of the pendulum at the lowest point is 0.39 Joule