Electrical energy.................
Answer:
40,000N
Explanation:
Force = Acceleration × Mass
2000×20=40,000
Yes, acceleration only tells you how velocity is changing. It doesn't say anything about what velocity is at any given time.
For example, if you set your car to cruise control on the highway going 80 mph. That is a constant high velocity, yet the car has 0 acceleration.
The opposite is also true. After a red light turns green, you put foot on the gas to accelerate. However, your velocity is initially low even though it has high acceleration.
Answer: No. Circuit should be closed.
Explanation:
A changing magnetic field induces emf in a circuit which is placed in it. This induced emf causes current to flow through it. This is given by Faraday's law which states that induced emf results due to rate of change of magnetic flux.

Current flows only through a closed circuit. Thus, when a wire is moved up and down in a magnetic field, it will not induce emf because the wire does not form a loop. It is an open circuit.
Stars are not really planets because they are far, far away from our solar system.
Hope this is helpful~