Answer:
Part a)

Part b)

Explanation:
As we know that magnetic flux through the loop is given as

now we have

now rate of change in flux is given as

now we know that



Now plug in all data


Part b)
Now the radius of the loop after t = 1 s



Now plug in data in above equation


Answer:
605 km
Explanation:
Hello
the same units of measure should be used, then
Step 1
convert 42 m/s ⇒ km/h
1 km =1000 m
1 h = 36000 sec


Step 2
find kilometers traveled after 4 hours

V,velocity
s, distance traveled
t. time
now, isolating s

and replacing

S=604.8 Km
Have a great day
I thinks its period because they are on the last column to the right