Answer: a) 12 Ω; b) 15.10 m; c) 360 kJ
Explanation: In order to explain this problem we have to considere the OHM law which is given by:
V=R*I where R is the resistance and I the current, V is the voltage.
For the toaster heating the resistance must be equal
R=V/I=120/10= 12 Ω
We also know that R=ρ*L/A where L and A are the length and area of the wire.
Then the length of the wire is given by:
L=R*A/ρ= 12*π*(0.8*10^-3)^2/1.6*10^-6=15.10 m
Finally we can calculate the consumed energy by the toaster heating during 5 minutes (5*60s=300 s).
The power is equal:
P=I*V= 10*120=1200 W
E= P*time (s)= 1200*300=360*10^3J
Answer:
C
Explanation:
i belive it's C may i be marked brainleist
Answer:
12 volts
Explanation:
4 + 4 + 4 = 12 volts all volts on parallel circuit are the same
If you mean in mass, then the mass of one proton is approximately equal to the mass on one neutron. If you mean how many of each, then the number of protons is equal to the number of electrons. If the number of electrons was different from the number of protons, then you'd have an ion. An ion with a positive charge is a cation, and an ion with a negative charge is an anion.
Answer:
D) Roger is incorrect. Only a chemical change is taking place as evidenced by the light and heat of the burning candles.
Explanation:
- A physical change is a change in which there is no formation of new substances. Examples of physical changes are the melting or the evaporation of a substance (all phase transitions are examples of physical changes): in such cases, there is no formation of new substances.
- A chemical change is a change in which new substances form. Examples of chemical changes are the chemical reactions: for instance, when a candle burns, a reaction is taken place (oxygen is burnt, transforming into carbon dioxide + heat + light, so this is an example of chemical change).
Therefore, the correct answer is
D) Roger is incorrect. Only a chemical change is taking place as evidenced by the light and heat of the burning candles.
