Answer:
(a) 
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:

where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:

(b)
Now, for 90% radiator blackbody at 2000 K:

<u>P = 0.816 Watt</u>
so you just take 110 divided by 7 and then you get the answer and times tthat by 20 and you get you answer which is 314.28 milligrams of sodium in 20 ounces of the sports drink.
Answer:
total momentum = 8.42 kgm/s
velocity of the first cart is 3.660 m/s
Explanation:
Given data
mass m1 = 2.3 kg
mass m2 = 1.5 kg
final velocity V2 = 4.9 m/s
final velocity V3 = - 1.9 m/s
to find out
total momentum and velocity of the first cart
solution
we know mass and final velocty
and initial velocity of second cart V1 = 0
so now we can calculate total momentum that is m1 v2 + m2 v2
total momentum = 2.3 ×4.9 + 1.5 ×(-1.9)
total momentum = 8.42 kgm/s
and
conservation of momentum is
m1 V + m2 v1 = m1 v2 + m2 v3
put all value and find V
2.3 V + 1.5 ( 0) = 2.3 ( 4.9 ) + 1.5 ( -1.9)
V = 8.42 / 2.3
V = 3.660 m/s
so velocity of the first cart is 3.660 m/s
Explanation:
Let
are the number of turns in primary and secondary coil of the transformer such that,

A resistor R connected to the secondary dissipates a power 
For a transformer, 

...............(1)
The power dissipated through the secondary coil is :


.............(2)
Let
are the new number of turns in primary and secondary coil of the transformer such that,

New voltage is :

...............(3)
So, new power dissipated is 





So, the new power dissipated by the same resistor is 6400 watts. Hence, this is the required solution.
Time should not be messed with
for bad things could happen
so think before you act or you'll regret it