Answer:
Explanation:
Thermal conductivity of glass pane = .8 W / m K
For conduction of heat , the formula is as follows
Q = 
; Q is heat conducted in time t by a medium of thickness d , area of cross section A and ( T₁ - T₂ ) is the temperature difference .
Putting the values in the equation
Q = 
= 103225.8 W
b )
energy lost in one day
= 103225.8 x 24 x 60 x 60
= .89187 x 10¹⁰ J .
When a person jumps from a tree to ground, what happens to the momentum of the person upon striking the ground is that it is transferred to earth. The momentum is not lost, it is conserved by being transferred to the ground. But it can also be lost to the impulse.
Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
Answer:
Explanation:
the relation between current, voltage and resistance in an electrical circuit is given by Ohm's law:
where V is the voltage, I is the current and R is the resistance. In this problem, the current is I=2 A, the voltage is V=120 V, therefore we can arrange the previous equation and find the resistance:
