Answer:
62.5 %
Explanation:
Let the initial intensity of unpolarized light is Io.
After first polariser the intensity of light becomes I'.
So, 
Now it passes through another polariser. The angle between the first polariser and the second polariser is given by Ф. The intensity is I''.
According to the law of Malus
Here, Ф = 30 degree
The percentage change in the intensity is given by
= 62.5 %
Answer:
amplifying signals is the correct answer
Explanation:
Answer:
7.53 m
Explanation:
Force, F = 47 N
initial velocity, u = 0
Final kinetic energy, Kf = 354 J
Let the distance traveled by the student is s.
According to the work energy theorem,
Work done by all forces = Change in kinetic energy
Force x distance = final kinetic energy - initial kinetic energy
F x s = kf - ki
47 x s = 354
s = 7.53 m
Vo = 5.89 m/s Y = 1.27 m g = 9.81 m/s^2
Time to height
Tr = Vo / g Tr = (5.89 m/s) / (9.81 m/s^2) Tr = 0.60 s
Max height achieved is:
H = Vo^2 / [2g] H = (5.89 )^2 / [ 2 * (9.81) ] H = (34.69) / [19.62] H = 1.77 m
It falls that distance, minus Andrew's catch distance:
h = H - Y h = (1.77 m) - (1.27 m) h = 0.5 m
Time to descend is therefore:
Tf = √ { [2h] / g ] Tf = √ { [ 2 * (0.5 m) ] / (9.81 m/s^2) } Tf = √ { [ 1.0 m ] / (9.81 m/s^2) } Tf = √ { 0.102 s^2 } Tf = 0.32 s
Total time is rise plus fall therefore:
Tt = Tr + Tf Tt = (0.60 s) + (0.32 s) Tt = 0.92 s (ANSWER)
<span>The amount of heat energy needed to increase the temperature of a substance by </span>
<span> is given by:
</span>
<span>
where m is the mass of the substance, Cs is its specific heat capacity and </span>
<span> is the increase in temperature of the substance.
In this problem, we have a certain mass m of gold, with specific heat capacity </span>
<span>, to which we add Q=2825 J of energy. Its temperature increases by </span>
<span>. Therefore, if we re-arrange the previous equation, we can find the mass of the block of gold:
</span>
<span>
So, the correct answer is B.</span>
