Answer:
the inertia provides the tendency to maintain speed and keep moving
The question is incomplete, the complete question is;
A body initially at a all 100 degree centigarde cools to 60 degree centigarde in 5 minutes and to 40 degree centigarde in 10 minutes . What is the temperature of surrounding? What will be the temperature in 15 minutes?
Answer:
See explanation
Explanation:
From Newton's law of cooling;
θ1 - θ2/t = K(θ1 + θ2/2 - θo]
Where;
θ1 and θ2 are initial and final temperatures
θo is the temperature of the surroundings
K is the constant
t is the time taken
Hence;
100 - 60/5 = K(100 + 60/2 - θo)
100 - 40/10 = K(100 + 40/2 - θo)
8= (80 - θo)K -----(1)
6= (70 - θo)K -----(2)
Diving (1) by (2)
8/6 = (80 - θo)/(70 - θo)
8(70 - θo) = 6(80 - θo)
560 - 8θo = 480 - θo
560 - 480 = -θo + 8θo
80 = 7θo
θo = 11.4°
Again from Newton's law of cooling;
θ = θo + Ce^-kt
Where;
t= 0, θ = 60° and θo = 11.4°
60 = 11.4 + C e^-K(0)
60 - 11.4 = C
C= 48.6°
To obtain K
40 = 11.4 + 48.6e^-10k
40 -11.4 = 48.6e^-10k
28.6/48.6 = e^-10k
0.5585 = e^-10k
-10k = ln0.5585
k= ln0.5585/-10
K= 0.0583
Hence, the temperature in 15 minutes;
θ= 11.4 + 48.6e^(-0.0583 × 15)
θ= 31.7°
Sound pressure decreases with distance, so there's less sound pressure acting on your ear-drum.
Your answer should be A.km/s does s mean speed?
A piece of purple plastic is charged with 3. 13×106 extra electrons compared to its neutral state, then the net electric charge in coulomb would be - 5.008×10⁻¹³ coulombs.
<h3>What is an electric charge?</h3>
Charged material experiences a force when it is exposed to an electromagnetic field due to the physical property of electric charge. You can have a positive or negative electric charge (commonly carried by protons and electrons respectively). Unlike charges attract one another while like charges repel one another. We refer to an object as neutral if it has no net charge.
The charge on one electron is -1.6 ×10⁻¹⁹ coulomb.
Then the charge on the 3.13×10⁶ extra electrons compared to its neutral state
=-1.6×10⁻¹⁹ ×(3.13×10⁶)
As given in the problem A piece of purple plastic is charged with 3.13×10⁶ extra electrons compared to its neutral state then the net electric charge in coulombs would be - 5.008×10⁻¹³ coulombs.
Learn more about an electric charge from here
brainly.com/question/8163163
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