Answer: T = -0.213°c
Heat flow = 38.2 w/m²
Explanation:
given data:
Wood = 0.031m thick
Styrofoam = 0.023m thick
Wood = k ( 0.080W/m.k)
Styrofoam = k (0.010W/m.k)
Temperature of wood = -15°c
Temperature of styrofoam = 19°c
(a) heat flow in wood and styrofoam must be equal
KAdT/ L = KAdT/ L
0.080 * A * ( T - ( -15) ) / 0.031 = 0.010 * A * ( T - ( 19°c) ) / 0.023
T = -0.213°c
(b) heat flow
H = KAdT / L
H = 0.080 * A * ( -0.213°c - ( -15°c) ) / 0.031
= 38.2 w/m²
ok so im not that good when it comes to physics but i think its C)
Answer:
a) 25.5 µH
b) 22.95 mV
Explanation:
Induced emf in a inductor is given by
E = L * di/dt, where
E is the voltage of the circuit
L is the inductance of the circuit
di/dt if the rate of inductance
A
So we have
0.0037 = L * 145
L = 0.0037 / 145
L = 0.0000255
L = 25.5 µH
B
i(t) = 225t²
Recall that
E = L * di/dt, so that
E = 25.5 µH * |225t²|
Differentiating with respect to t, we have
E = 25.5 * 2 * 225t
E = 25.5 * 450t
Solving for t = 2,we get
E = 25.5 * 450(2)
E = 25.5 * 900
E = 22950 µV or
E = 22.95 mV
Answer:
The time interval is 
Explanation:
From the question we are told that
The angular acceleration is 
The time taken is 
The angular displacement is 
The angular displacement can be represented by the second equation of motion as shown below
where 
is the initial velocity at the start of the 4 second interval
So substituting values
=> 
Now considering this motion starting from the start point (that is rest ) we have
Where 
is the angular velocity at rest which is zero and 
is the angular velocity after 4.0 second which is calculated as 12 rad/s s
=>
Answer:
The human ear is not sensitive to every frequency of sound, rather, our hearing range is from 20Hz to 20,000Hz. This means sound frequencies outside this range are not audible to the human ear, which is why not every sound produced is heard. This is quite a blessing because if we could hear every vibrating body, then our ears would never stop listening: we won't be able to distinguish 'important sounds' from unimportant ones, rendering our ears effectively useless. Perhaps this is why we have a hearing range in the first place: sounds of our friends and our foes lie in 20Hz-20kHz range.
