3.what does this stand for ??

see below

Explanation:

The triangle stands for the change in

We would change the change in x

Δ This is the symbol of Delta which means Change

and x is length/distance/position.

Thus, Δx stands for Change in length/distance/position.

-TheUnknownScientist

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer