Answer:
The time taken by the brick to hit the ground, t = 0.84 s
Explanation:
Given that,
A brick falls from a height, h = 3.42 m
The initial velocity of the brick is zero.
Since the brick is under free-falling. The time equation of a free-falling body when the displacement is given is
t = 
where,
h - height from surface in meters
g - acceleration due to gravity
on substituting the values in the above equation,
t = 
= 0.84 s
Hence, time taken by the brick to hit the ground is t = 0.84 s
Answer:
* most of the emission would be in the infrared part, the visible radiation would be very small.
*total intensity of the semition decreases that the intensity depends on the fourth power of the temperature
Explanation:
The radiation emitted by the Sun is approximately the radiation of a black body, if the Sun were to cool, the maximum emission wavelength changes
λ T = 2,898 10⁻³
λ = 2,898 10⁻³ / T
if the temperature decreases the maximum wavelength the greater values are moved, that is to say towards the infrared. Therefore the emission curve also moves, in this case most of the emission would be in the infrared part, the visible radiation would be very small.
Furthermore, the total intensity of the semition decreases that the intensity depends on the fourth power of the temperature according to Stefan's law
P = σ A eT⁴
Answer:
Local action is removed by amalgamating zinc rod.
Explanation:
This prevents chemical reaction to occur because impurities in the zinc cannot get into contact with an electrolyte.
Answer:
(a) The self inductance, L = 21.95 mH
(b) The energy stored, E = 4.84 J
(c) the time, t = 0.154 s
Explanation:
(a) Self inductance is calculated as;
where;
N is the number of turns = 1000 loops
μ is the permeability of free space = 4π x 10⁻⁷ H/m
l is the length of the inductor, = 45 cm = 0.45 m
A is the area of the inductor (given diameter = 10 cm = 0.1 m)
(b) The energy stored in the inductor when 21 A current ;
(c) time it can be turned off if the induced emf cannot exceed 3.0 V;
