The ocean is salty because it contains many dissolved ions. As these charged particles move with the water in strong ocean currents, they feel a force from the earthâs magnetic field. Positive and negative charges are separated until an electric field develops that balances this magnetic force. This field produces measurable potential differences that can be monitored by ocean researchers. The Gulf Stream moves northward off the east coast of the United States at a speed of up to 3.5 m/s . Assume that the current flows at this maximum speed and that the earthâs field is 50 μT tipped 60 degrees below horizontal. Part A
What is the direction of the magnetic force on a singly ionized negative chlorine ion moving in this ocean current? Choose best answer
(a) east
(b) west
(c) up
(d) down
Part BWhat magnitude electric field is necessary to exactly balance this magnetic force?
Choose best answer.
(a) 1.8 x 10-4 N/C
(b) 1.5 x 10-4 N/C
(c) 1.0 x 10-4 N/C

Given that,

Speed = 3.5 m/s

Magnetic field = 50μT

Angle = 60°

(A). We need to find the direction of magnetic force

Using formula of magnetic force

Here, = down

But , charge is negative.

So, the direction of magnetic force will be up.

(B). We need to calculate the magnetic electric field

Using formula of magnetic force

Where, v = speed

B = magnetic field

Put the value into the formula

Hence, (A). The direction of magnetic force is UP

(c) is correct option

(B). The magnetic electric field is

(b) is correct option

the answer is kevlar

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.