initially coin is at rest and then it drop for total time t = 1.5 s
so here the speed of the coin at which it will hit the floor is to be find
here we know that
a = 9.8 m/s^2
t = 1.5 s
now from above equation
so it will hit the floor with speed 14.7 m/s
Answer:
1. The frequency of the incident light must be equal to or greater than the threshold frequency of the photons before emission could take place.
2. The intensity of the incident light is proportional to the amount of photons released. The higher the intensity of light, the greater the amount of photons ejected.
Explanation:
1. Photoelectric effect is the process by which light with sufficient frequency falls on the surface of a material, e.g metal, to emit electrons. The incident light must have a minimum value of required frequency for the electrons to be ejected. This energy is termed work function which is a function of frequency.
So for emission to take place, the frequency of the incident light must be equal to or greater than the threshold frequency of the photons.
2. The intensity of light is a measure of the amount of light per unit area. When the intensity of incident light increases, the probability that photons would be released increases. The intensity of the incident light is proportional to the amount of photons released.
The correct answer to the question is that the lost mass has been converted into energy.
EXPLANATION:
From Einstein's theory, we know that energy and mass are inter convertible .
When some amount of mass is lost, same amount of energy equivalent to mass is produced.
Let us consider m is the mass lost during any reaction. Hence, the amount of energy produced will be-
Energy E =
Here, c is the velocity of light i.e c =
As per the question, uranium-235 undergoes fission. The amount of mass defect is 0.1 %.
The mass defect is defined as the difference between mass of reactants and products. During the fission, energy is produced.
The energy produced in this reaction is nothing else than the energy equivalent to mass defect. Approximately 199.5 Mev of energy equivalent to this mass defect is produced in this reaction.
Answer:
Explanation:
We shall solve this problem on the basis of pinciple that water is incompressible so volume of flow will be equal at every point .
rate of volume flow of one stream
= cross sectional area x velocity
= 8.4 x 3.5 x 2.2 = 64.68 m³ /s
rate of volume flow of other stream
= 6.6 x 3.6 x 2.7
= 64.15 m³ /s
rate of volume flow of rive , if d be its depth
= 11.2 x d x 2.8
= 31.36 d
volume flow of river = Total of volume flow rate of two streams
31.36 d = 64.15 + 64.68
31.36 d = 128.83
d = 4.10 m /s .