Answer:
Time taken = 10400 s
Explanation:
Given:
Initial speed of the train,
Final speed of the train,
Displacement of the train,
Using Newton's equation of motion,
Now, using Newton's equation of motion for displacement,
Now, plug in the value of in the above equation. This gives,
Now, plug in 234000 m for , 25 m/s for
and 20 m/s for
. Solve for
.
Therefore, the time taken by the train is 10400 s.
Answer:
B)
Explanation:
The electric force between charges can be determined by;
F =
Where: F is the force, k is the Coulomb's constant, is the value of the first charge,
is the value of the second charge, r is the distance between the centers of the charges.
Let the original charge be represented by q, so that;
= 2q
=
So that,
F = x
= 2q x x
= x
= x
F = x
The electric force between the given charges would change by .