A surfer travels on the crest of a surface wave
Answer:
The mass of the Al-duckie should be 30 kg.
Explanation:
We will use the first law of thermodynamics:
ΔU = m·Cv·ΔT
Since the specific heat of water is 4.185 J(gºC), the change in the water's internal energy would be:
ΔU = 100 kg · 4.185 J(gºC) · (42ºC - 38ºC) = 1674 KJ
Given that no heat is lost, all the internal energy that the water loses while cooling down will transfer to the duckie. So, if the duckie has ΔU = 1674 KJ and its final temperature is the desired 38 ºC, we can calculate its mass using the first law again:
![m=\frac{\Delta{U}}{Cv{\Delta{T}}}=\frac{1674}{0.9*[38-(-24)]}=30Kg](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B%5CDelta%7BU%7D%7D%7BCv%7B%5CDelta%7BT%7D%7D%7D%3D%5Cfrac%7B1674%7D%7B0.9%2A%5B38-%28-24%29%5D%7D%3D30Kg)
Answer:
Option B) C and D
Explanation:
The amount of charge passing through a resistor each second corresponds to the definition of current, so the problem is asking "which resistors have the same amount of current".
Let's keep in mind that:
- When two resistors are in series (=they are connected into the same branch of the circuit), the current flowing through each resistor is the same
- When two resistors are in parallel (=they are connected into different branches), the potential difference across each resistor is the same
Looking at the previous definitions, we have to find the two resistors in the circuit that are connected in series. We see that resistors C and D are in the same branch, so they are in series: therefore, the current flowing through resistor C and D is the same.
There’s many types of electricity that comes from an outlet, like [15A, 120 Volt Outlets] those are more common in older homes and can come in two versions [Two-pronged outlet and three-pronged version]
