Answer:
Induced emf, 
Explanation:
The varying magnetic field with time t is given by according to equation as :

Where
are constant
Let
is the emf induced in the loop as a function of time. We know that the rate of change of magnetic flux is equal to the induced emf as:





So, the induced emf in the loop as a function of time is
. Hence, this is the required solution.
Answer:
the spring be displaced by 25.0 cm
Explanation:
The computation is shown below:
As we know that
F= -K × x
So,

Now

= -0.250m
= 25.0 cm
Hence, the spring be displaced by 25.0 cm
Answer is: 1973.17N aprox.
step by step in the pic below
We don't know the change in velocity, so can't answer.
Answer:
4 km/hr
Explanation:
The computation of the actual velocity is shown below:
Because the path of its paddles is opposed to the current direction, the real velocity can be determined by deducting the current velocity to its velocity while paddling
So, the actual velocity is
= Upstream - downstream
= 19 km/hr - 15 km/hr
= 4 km/hr
As we can see it is in positive, so it is an upstream direction