Answer: Negative
Explanation:
An oxygen atom has the chemical symbol O. Its atomic number is 8, with an electronic configuration of 1s2, 2s2 2p4.
Now, due to the incompletely filled p-orbital, oxygen picks up two additional, free-floating electrons (2e-) to complete its outermost shell. And since each electrons received carries a negative charge, oxygen atom becomes a negatively charged divalent ion, O2-
See the equation below
O + 2e- ---> O2-
Answer:
the weight of the object, the force of gravity acting on said object, and the mass of the object are needed for Newton's second law of motion.
Answer:
I answered :)
Explanation:
i just dk the right answer
Answer:
Sam is providing the biggest power i.e. 50 W
Explanation:
Sam is moving house and is carrying a 300N box of books up a flight of steps 5m high, it takes her 30 seconds.
Sam's power :
Gary follows her carrying a bag of clothes doing 1000 J of work; it only takes him 25 seconds.
Gary's power :
So, it is clear that Sam is providing the biggest power.
The answer is 35 minutes
The Newton's law of cooling is:
T(x) = Ta + (To - Ta)e⁻ⁿˣ
T(x) - the temperature of the coffee at time x
Ta - the ambient temperature
To - the initial temperature
n - constant
step 1. Calculate constant k:
We have:
T(x) = 200°F
x = 10 min
Ta = 68°F
To = 210°F
n = ?
T(x) = Ta + (To - Ta)e⁻ⁿˣ
200 = 68 + (210 - 68)e⁻ⁿ*¹⁰
200 = 68 + 142 * e⁻¹⁰ⁿ
200 - 68 = 142 * e⁻¹⁰ⁿ
132 = 142 * e⁻¹⁰ⁿ
e⁻¹⁰ⁿ = 132/142
e⁻¹⁰ⁿ = 0.93
Logarithm both sides with natural logarithm:
ln(e⁻¹⁰ⁿ) = ln(0.93)
-10n * ln(e) = -0.07
-10n * 1 = - 0.07
-10n = -0.07
n = -0.07 / - 10
n = 0.007
Step 2. Calculate time x when T(x) = 180°F:
We have:
T(x) = 180°F
x = ?
Ta = 68°F
To = 210°F
n = 0.007
T(x) = Ta + (To - Ta)e⁻ⁿˣ
180 = 68 + (210 - 68)e⁻⁰.⁰⁰⁷*ˣ
180 - 68 = 142 * e⁻⁰.⁰⁰⁷*ˣ
112 = 142 * e⁻⁰.⁰⁰⁷⁾*ˣ
e⁻⁰.⁰⁰⁷*ˣ = 112/142
e⁻⁰.⁰⁰⁷*ˣ = 0.79
Logarithm both sides with natural logarithm:
ln(e⁻⁰.⁰⁰⁷*ˣ) = ln(0.79)
-0.007x * ln(e) = -0.24
-0.007x * 1 = -0.24
-0.007x = -0.24
x = -0.24 / -0.007
x ≈ 35
