Answer:
Explanation:
The wires are in circular shape . They have common center .
magnetic field due to circular wire is given by the formula
B = 
where I is current , r is radius of the coil .
magnetic field due to inner wire
= 
magnetic field due to outer wire
= 
These should be equal and opposite so that by cancelling each other , they create zero field.
= 
I = 16.66 A
Direction of current should be in opposite direction ie anticlockwise when looking from above.
Answer:
a) 
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
a = Acceleration

The acceleration of the bicycle and rider is -1.5 m/s²
Force

The magnitude of the average force needed to bring the bicycle and its rider to a stop is 
Answer:
41.1 ÷ 40.0
Explanation:
Did you learn about Newton
Down stream it would be going 20 mph and up stream 10 mph