Answer:
Explanation:
Work function of aluminium is 4.1 eV .
Therefor light of minimum energy of 4.1 eV will be required to cause the emission of electrons.
If we use this frequency of light or energy of light to effect ejection of photoelectrons from cesium , it will be easily ejected because energy requirement for this metal is lower ( work function is lower 2.1 eV ). than the energy of photon falling on it.
If we use this frequency of light or energy of light to effect ejection of photoelectrons from aluminium , it will be not ejected because energy requirement for this metal is high ( work function is higher 5.1 eV ) . Even if we increase the intensity of light , electrons will not be ejected because energy of each photon depends upon the frequency .
Answer:
The answer is 271.3 joules .
Explanation:
Work = (weight) x (distance)
Work = (50 lb) x (1 kg / 2.20462 lb) x (9.81 newton/kg)
x (4 feet) x (1 meter / 3.28084 feet)
= (50 x 9.81 x 4) / (2.20462 x 3.28084) newton-meter
= 271.3 joules .
We don't need to know how long the lift took, unless we
want to know how much power he was able to deliver.
Power = (work) / (time)
= (271.3 joule) / (5 sec) = 54.3 watts .
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The easy way:
Work = (weight) x (distance)
= (50 pounds) x (4 feet) = 200 foot-pounds
Look up (online) how many joules there are in 1 foot-pound.
There are 1.356 joules in 1 foot-pound.
So 200 foot-pounds = (200 x 1.356) = 271.2 joules.
credits original answer AL2006
The answer is D) second/meter
Answer:
The kinetic energy of a body is the energy that it possessed due to its motion. Kinetic energy can be defined as the work needed to accelerate an object of a given mass from rest to its stated velocity. Kinetic energy depends upon the velocity and the mass of the body.