Answer:
Useable energy, electricity
Answer:
Frequency = 658 Hz
Explanation:
The third harmonics of A is,

The second harmonics of E is,

The difference in the two frequencies is,
delta_f = 1320 Hz - 1318 Hz = 2 Hz
The beat frequency between the third harmonic of A and the second harmonic of E is,
delta_f = 

We have calculate the frequency of the E string when she hears four beats per second, then
delat_f = 4 Hz


Hope this helps!
Catalysts
a catalyst is something added to a reaction that speeds it up (or lowers the activation energy)
increasing the temp would speed up the whole reaction but not lower the activation energy
so B.
Answer:
D. move up to another shell that would form
Explanation:
An atom has protons, neutrons and electrons. Protons and neutrons are present in the nucleus and electrons orbit the nucleus in fixed shells. An electron can jump to higher shell when it gains energy and lower one when it loses energy. Thus, when single electron in hydrogen atom is given a small amount of energy, it would jump to another higher shell.
Answer:
22 N upward
Explanation:
From the question,
Applying newton's second law of motion
F = m(v-u)/t....................... Equation 1
Where F = Average force exerted by the ground on the ball, m = mass of the baseball, v = final velocity, u = initial velocity, t = time of contact
Note: Let upward be negative and downward be positive
Given: m = 0.14 kg, v = -1.00 m/s, u = 1.2 m/s, t = 0.014 s
Substitute into equation 1
F = 0.14(-1-1.2)/0.014
F = 0.14(-2.2)/0.014
F = 10(-2.2)
F = -22 N
Note the negative sign shows that the force act upward