Answer:
D and A
Explanation:
Hint The basic difference between them is that a bar magnet is a permanent magnet whereas an electromagnet is a temporary magnet. An electromagnet is formed when an electric current is passed through wires wound around soft metalcore. An electromagnet loses its magnetism once the current flow is stopped.
Answer:
11700j
Explanation:
add the two because the plate has to maintain the temp.
2700+9000=11700
Heptane is always composed of 84.0% carbon and 16.0% hydrogen. This illustrates the "law of definite proportions".
Answer: Option C
<u>Explanation:</u>
Proust's law states that every chemical compound used to made up of element constituents with constant proportions in terms of its mass and also independent from its sources and synthesis method. In 1779, Joseph Proust gave other names to the Proust's law as, the law of composition or definite proportions or constant compositions.
This can understood from given example like: Oxygen is composed of 8/9 of the mass of any sample of pure water while the hydrogen fills up the remaining 1/9 of the mass. The basis of stoichiometry is structured with the law of multiple proportions along the law of definite proportions.
in case you dont want to read the answer is B
Answer:48.2 Joules
Explanation:
Given
two masses of 0.2 kg and 0.4 kg collide with each other
after collision 0.2 kg deflect 30 north of east and 0.4 kg deflects 53.1 south of east
Velocity of 0.2 kg mass is


Velocity of 0.4 kg mass


Thus total Kinetic energy 
Kinetic energy=48.2 J