Answer: -7J
Explanation:
To determine the change in potential energy, use the equation ΔPE=mgΔh
Δ
PE=mg
Δ
h
, where m is the mass, g= 9.8 m/s2
g= 9.8 m/s
2
, and Δh is the change in height. Hence, we have that the potential energy PE=4.0 kg×9.8 m/s2×-2.0 m=-78 J
PE=4.0 kg
×
9.8 m/s
2
×
-2.0 m=-78 J
. To verify that this is correct, note that since the cat changes the potential energy to kinetic energy by jumping, the potential energy decreases. Hence, the potential energy should be negative.
Answer:
it means it has pressure of 13.6 CM mercury on an area
10 m/s2 for a distance of 65.2 ft
Answer:
Initial state Final state
3 ⇒ 2
3 ⇒ 1
2 ⇒ 1
Explanation:
For this exercise we must use Bohr's atomic model
E = - 13.606 / n²
where is the value of 13.606 eV is the energy of the ground state and n is the integer.
The energy acquired by the electron in units of electron volt (eV)
E = e V
E = 12.5 eV
all this energy is used to transfer an electron from the ground state to an excited state
ΔE = 13.6060 (1 / n₀² - 1 / n²)
the ground state has n₀ = 1
ΔE = 13.606 (1 - 1/n²)
1 /n² = 1 - ΔE/13,606
1 / n² = 1 - 12.5 / 13.606
1 / n² = 0.08129
n = √(1 / 0.08129)
n = 3.5
since n is an integer, maximun is
n = 3
because it cannot give more energy than the electron has
From this level there can be transition to reach the base state.
Initial state Final state
3 ⇒ 2
3 ⇒ 1
2 ⇒ 1
Answer:
160 m
Explanation:
The intensity, I, of the sound is inversely proportional to the square of the distance, r, from the source.

Hence,


From the question,
is half of 


