What is the motional emf of the loop at time t = 0.032 s?

[hime]

Homework Statement

A conducting loop is made in the form of two squares of sides s1 = 3.8cm and s2 = 6 cm as shown. At time t = 0, the loop enters a region of length L = 18.6 cm that contains a uniform magnetic field B = 1.2 T, directed in the positive z-direction. The loop continues through the region with constant speed v = 40 cm/s. The resistance of the loop is R = 2.8 O.

At time t = t1 = 0.032 s, what is I1, the induced current in the loop? I1 is defined to be positive if it is in the counterclockwise direction.

Hint: The induced emf in the loop is not equal to the flux through the loop, but rather the time derivative of the flux through the loop.

Homework Equations

Velocity = distance/time
emf = -B.dA/dt

The Attempt at a Solution

total moving length =L+s1+s2=28.4cm

time=D/v= 28.4/40 =0.71s

At t=0.035s , the distance is 1.4 cm w
distance=velocity.time = 40.(0.035) = 1.4cm

this distance we can take as entering length of the loop.
For L=1.4cm, Area at time(dA/dt) = L*W = 1.4(3.8)cm^2 = 5.32*10^-4 m^2

e.m.f in the loop of this area:
e=-B.dA/dt=1.2*5.32*10^-4 v = 6.384 *10^-4 v
the induced current at this time i=e/R = 6.384*10^-4/2.8 (R=2.8 ohm given) = 0.228 mA

But, its not the correct answer> Help! What am I doing wrong?

 

[hime]

EDiT:

To do this problem, I know that we first have to find motional emf of the loop at time t =0.032 s? I also know that emf= BxvL where v is the velocity where L= velocity*time

But when I try to plug in numbers I'm getting a wrong answer.
emf= 1.2*.4*(.4*.032) = 0.006144 Volts