In the photoelectric effect, the energy given by the incoming photon is used partially to extract the electron from the metal (work function) and the rest is converted into kinetic energy of the electron:
where
hf is the energy of the photon, with h being the Planck constant and f the frequency of the photon
is the work function
K is the kinetic energy of the electron
When K=0, we have the minimum energy required to extract the electron from the metal, so the equation becomes
(1)
If we convert the work function of gold into Joules:
We can re-arrange eq.(1) to find the minimum energy of the photon:
When we jump from the truck and accelerate towards the earth surface, the earth also accelerates towards us but it's acceleration is very negligible.
To find the answer, we need to know about the acceleration of earth due to the gravitational attraction.
<h3>What's the gravitational force between the earth and a person?</h3>
- Gravitational attraction force is GMm/r² between the earth and a person.
- M= mass of the earth
m= mass of the person
r= separation between them.
<h3>What's the acceleration of the earth towards the person when he jumps from a truck?</h3>
- According to Newton's second law, Force = M×acceleration
- Acceleration= Force / M
- Here, Force = GMm/r²,
so acceleration of earth= Gm/r²
- As this acceleration is very small, so we can't notice it.
Thus, we can conclude that the earth also accelerates towards us.
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Answer:
Explanation:
Force is the push or pull on object that can cause different things, like acceleration. According to Newton's 2nd Law of Motion, it is the product of mass and acceleration.
The mass of the wolf is 50.5 kilograms and the acceleration is 5.0 meters per square second. Therefore:
Substitute the values into the formula.
Multiply.
- 1 kilogram meter per square second is equal to 1 Newton.
- Our answer of 252.5 kg*m/s² is equal to 252.5 Newtons.
The force required is <u>252.5 Newtons</u>.
The length to which the pendulum will be adjusted to keep perfect time is 29.59 inches. See the explanation below.
<h3>What is the justification for the above answer?</h3>
T1 = 2πR√(L1/GM)
and
T2 = 2πR√(L1/GM)
T1/T2 = √(L1/L2).
If the pendulum has an efficient period, that means it executes with perfect frequency.
Thus,
T2 = (24 * 60)/x
= 1440/x
This means that in one day, there are perfect cycles of represented by "x". Note that there are 1440 minutes in one day.
If the other Pendulum is slower by 10 minutes, that means
T1 = 1450/x
Hence
(1450/x)/(1440/x) = √(L1/L2).
⇒ 1450/1440 = √(L1/L2).
Thus,
(1450/1440)² = 30/L
L = 30/(1450/1440)²
L = 30/(1.00694444444)²
L = 30/1.01393711419
L = 29.5876337695
L 
29.59 inches.
Hence, the pendulum will need to be adjusted by 29.59 inches to ensure that the clock keeps perfect time.
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Answer:
D a conclusion
Explanation:
The definition of hypothesis is a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation
