Answer:
ΔT=-747,13°C
Explanation:
Sensible heat is<em> the amount of thermal energy that is required to change the temperature of an object</em>, the equation for calculating the heat change is given by:
Q=msΔT
where:
- Q, heat that has been absorbed or realeased by the substance [J]
- m, mass of the substance [g]
- s, specific heat capacity [J/g°C] (
- ΔT, changes in the substance temperature [°C]
To solve the problem, we clear ΔT of the equation and then replace our data:
Q=msΔT
ΔT=Q/ms
Δ
°C
<em>(Note that Q=-14900 J because there is a </em><u><em>LOST</em></u><em> of thermal energy)</em>
Thus, the change in temperature of the steel bar is -747,13°C, meaning that the temperature of the bar decreases.
Answer:
im not a brain wiz but i think 20
Explanation:
A form of
electricity which can attract things is static electricity. Static electricity
is the result of an imbalance between negative and positive charges in an
object. These charges built up o the surface of an object until they find a way
to e released or discharged causing the attraction of things.
Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
Answer:
The first and last choice
Hope this helps! Plz mark brainliest
