Answer:
The magnetic field at a distance x = 5 m is 1.59 nT
Explanation:
Length of the wire, L = 2 cm = 0.02 m
Current, I = 20 A
x = 5 m
Magnetic field at a distance x = 5 m due to an infinitely long wire is given by:


There are 12 blue marbles, because this can basically be modeled as 3/2 = 18/x, which can be solved by mutiplying 3 and 2 by 6
Answer:
6.5 m above the floor and 5 m above Christine's hand when it reaches the maximum height.
Explanation:
Let g = 10 m/s2 be the gravitational deceleration that affects the ball vertical motion so it comes to the maximum height at 0 speed. We can use the following equation of motion to find out the distance traveled by the ball from where it's thrown:

where v = 0 m/s is the final velocity of the ball when it reaches maximum level,
= 10m/s is the initial velocity of the ball when it starts, g = -10 m/s2 is the deceleration, and
is the distance traveled, which we care looking for:


So the ball is 5 m above Christine' hands when it reaches maximum height, and since the hand is 1.5 m above the floor, the ball is 5 + 1.5 = 6.5 m above the floor when it reaches maximum height.