Explanation:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .
1. False
2.False
3.False
4.True
5. True
6. False
7.True
8.False
9. True
10. False
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.
Here we know that
now from kinematics we have
now from above all values we have
so final angular speed is -12.6 rad/s
It would take millions of years to form a mountain as plates move very slowly and to form it first one plate should climb upon another. After this very slowly this hill will convert into a mountain.
