Answer:
1. 60 kg m/s
2. 2.4 kg
3. none they both have same momentum
Answer:
an electromagnet is a metal which has the ability to turn into a magnet on passing electricity through it .
But once the electric flow is withdrawn the circuit breaks and it no more behaves like a magnet.
but this is not so in permanent magnets
Explanation:
thus electromagnet is used in magnetic cranes bcoz their magnetism can be controlled conveniently.
Answer:
Explanation:
The index of refraction is equal to the speed of light c in vacuum divided by its speed v in a substance, or 
. For our case we want to use 
, which for our values is equal to:
Which we will express with 3 significant figures (since a product or quotient must contain the same number of significant figures as the measurement with the <em>least</em> number of significant figures):
Answer:
Energy
Explanation:
One ways of stating the law of conservation of energy is that "you cannot get more energy from a machine than the amount of energy you put into it".
The law of conservation of energy states that in a system, energy is neither created nor destroyed but transformed from one form to another.
The energy in a system does not increase based on the premise of this law.
- The efficiency of a machine can reduce but the energy is always conserved.
- This is because energy is transformed to other forms.
