I think you can google this because I really don’t know the answer I’m so sorry
Answer:
6s
Explanation:
Assume it is dropped from rest and the gravitational acceleration is 10
By the equation of motion under constant acceleration:

180 = (0)t+10(t^2)/2
t = 6 or -6 (rejected)
t = 6 s
Answer:
True
Explanation:
In this particular case, the area of the graph represents the impulse.
In fact, impulse is defined as the change in momentum of an object:

Moreover, impulse is also defined as the product between the magnitude of the force acting on an object and the duration of the collision:

If we plot a graph of the force versus the time, if the force is constant then this graph will have a rectangular shape, and the area under the graph will simply be the product

which corresponds to the definition of impulse.
Explanation:
If a metal rod of length L moves with velocity v is moving perpendicular to its length, in a magnetic field B, the induced emf is given by :

The electric field in the conductor is given by :

It is clear that the electric field is independent of the length of the rod. If the length of the rod is doubled, the electric field in the rod remains the same.