B. gas has no definite shape or volume. liquid has definite volume but no definite shape
Answer:
orange line
Explanation:
it is the only straight line that makes sense. curved lines imply velocity changed. and the completly flat green line implies the vehicle didn't move since its position value stayed the same. must be the downward pointing orange line
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>
Answer:
Reflection of light means the bouncing back of light in another direction after hitting a smooth polished surface
<h3>
<u>laws </u><u>of </u><u>reflection</u></h3>
1) Angie of incidence is equal to the angle of reflection
2) The nornal ray, reflected ray and the incident ray all lie in the same plane
Answer:
No work is done since no distance is given
Explanation:
Since no distance is given, the force is not doing any work
No work is done by the man since we do not know the distance or displacement.
Work is only said to be done when the force applied on an object moves it through a particular distance.
Work done = Force x distance.
Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.
