The total power emitted by an object via radiation is:
where:
A is the surface of the object (in our problem,
is the emissivity of the object (in our problem,
)
is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is
Substituting these values, we find the power emitted by radiation:
So, the correct answer is D.
Answer:
527 Hz
Solution:
As per the question:
Beat frequency of the player, 
Frequency of the tuning fork, f = 523 Hz
Now,
The initial frequency can be calculated as:
when
when
But we know that as the length of the flute increases the frequency decreases
Hence, the initial frequency must be 527 Hz
Impulse = (force) x (time)
The first impulse was (20 N) x (10 sec) = 200 meters/sec
The second one is (50 N) x (time) and we want it equal to the first one, so
(50 N) x (time) = 200 meters/sec
Divide each side by 50N : Time = 200/50 = <em>4 seconds</em>
By the way, the quantity we're playing with here is the cart's <em>momentum</em>.
Answer:
Explanation:
Given that, .
R = 12 ohms
C = 500μf.
Time t =? When the charge reaches 99.99% of maximum
The charge on a RC circuit is given as
A discharging circuit
Q = Qo•exp(-t/RC)
Where RC is the time constant
τ = RC = 12 × 500 ×10^-6
τ = 0.006 sec
The maximum charge is Qo,
Therefore Q = 99.99% of Qo
Then, Q = 99.99/100 × Qo
Q = 0.9999Qo
So, substituting this into the equation above
Q = Qo•exp(-t/RC)
0.9999Qo = Qo•exp(-t / 0.006)
Divide both side by Qo
0.9999 = exp(-t / 0.006)
Take In of both sodes
In(0.9999) = In(exp(-t / 0.006))
-1 × 10^-4 = -t / 0.006
t = -1 × 10^-4 × - 0.006
t = 6 × 10^-7 second
So it will take 6 × 10^-7 a for charge to reached 99.99% of it's maximum charge
Answer:
Explanation:
Given
volume 
Suppose base is square with side L
height of crate is h
Volume 
Cost of top and bottom area 
Cost of Side area 
Total Cost 
Total Cost 
Differentiate C w.r.t Length
Dimensions are 
