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:
Beats is a phenomenon which occurs when two sound waves with different frequencies overlap each other.
Explanation:
When these two sound waves overlap, a third frequency is formed. The places where the two waves reinforces each other, constructive interference takes place and a louder sound is produced whereas, at points where destructive interference takes place a softer sound is produced.
These alternative loud and soft sounds are called beats.
A pair of scissors .....................................
1m = 1000 mm
0,4m = 0,4 * 1000 = 400mm
Answer:
Explanation:
Here we know that initial temperature of ice is given as
now the latent heat of ice is given as
now we also know that the mass of ice is
so here we know that heat required to change the phase of the ice is given as
