Explanation:
- Speed is the rate of change of distance with time.
Speed = 
- Velocity is given as the displacement per unit of time:
Velocity = 
Speed and velocity are similar but speed is a scalar quantity while velocity is a vector quantity. Speed has magnitude but does not point towards a specific direction. Velocity shows both magnitude and direction and it is a vector quantity.
- Acceleration is given as the change in velocity with time. It is a vector quantity:
Acceleration = 
- Distance is how far a body moves. It is scalar quantity.
- Time is the duration of an event. It is a scalar quantity.
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Vector calculation brainly.com/question/2678571
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Answer:
Impulse is related to momentum because impulse is a term that describes object's change in momentum. The measurable quantity of momentum changing is called impulse.
Answer:
A) 1000 joules
Explanation:
In general work is given by the equation:
(1)
A) With 
the displacement and 
the force applied, because the force and the displacement are parallel (the crate is pushed horizontally) 
is simply 
, and because the path is a straight line and the force is constant work is:
(2),
B) The work-energy theorem says that the total work on a body is equal to the change on kinetic energy:
(3)
The total work on the crate is the work done by the push and plus the work of the friction 
(4) , as (A) because forces are parallel to the displacement 
(5) and 
(6), the due friction always has negative sign because is opposite to the displacement, using (6), (5) and (4) on (3):
(3)
C) The energy is lost by friction, so the amount of energy turned into heat is the work the friction does:
(3)
you are so wise how do you do it?
Answer:
c. The incident light must have at least as much energy as the electron work function
Explanation:
In photoelectric effect, electrons are emitted from a metal surface when a light ray or photon strikes it. An electron either absorbs one whole photon or it absorbs none. After absorbing a photon, an electron either leaves the surface of metal or dissipate its energy within the metal in such a short time interval that it has almost no chance to absorb a second photon. An increase in intensity of light source simply increase the number of photons and thus, the number of electrons, but the energy of electron remains same. However, increase in frequency of light increases the energy of photons and hence, the
energy of electrons too.
Therefore, the energy of photon decides whether the electron shall be emitted or not. The minimum energy required to eject an electron from the metal surface, i.e. to overcome the binding force of the nucleus is called ‘Work Function’
Hence, the correct option is:
<u>c. The incident light must have at least as much energy as the electron work function</u>
