Power = (voltage) x (current)
(1,200 W) = (120 V) x (current)
Current = (1,200 watt) / (120 volt) = 10 Amperes.
How long the heater heats is irrelevant. The current
is flowing all the time, whenever the heater is running.
Answer:
s = 1800 m = 1.8 km
Explanation:
The distance, the speed, and the time of reach of the sound are related by the following formula:

where,
s = distance
v = speed
t = time
FOR WATER:
---------------------- eq (1)
where,
s = distance between ship and diver = ?
= speed of sound in water = 1440 m/s
t = time taken by sound in water
FOR AIR:
---------------------- eq (2)
where,
s = distance between ship and diver = ?
= speed of sound in water = 344 m/s
t + 4 s = time taken by sound in water
Comparing eq (1) and eq (2),because distance remains constant:

t = 1.25 s
Now using this value in eq (1):

<u>s = 1800 m = 1.8 km</u>
Answer:
a) transparent
b) transparent
c) opaque
Explanation:
In the first one, the light rays go completely through, so it is transparent.
The second one I'm not too sure about. It is refraction so it's going through a different material, but the fact that it went through makes me say transparent.
Last one, the light rays are reflecting off the surface so it's opaque.
Please feel free to correct me if I'm wrong. This is just my understanding