Let vb be the velocity of the motorboat and let vs be the velocity of the stream.
We know that when she drives upstream the velocity is 8 m/s, in this scenario the velocities point in opposite directions, then we have the equations:
When she drives downstream the velocites point in the same direction then we have the equation:
hence we have the system of equations:
Solving the first equation for the velocity of the boat we have:
Plugging this in the second equation we have:
Therefore, the velocity of the stream is 2 m/s
Answer:
towards the south
Explanation:
When the electron enters the region with magnetic field, it experiences a magnetic force perpendicular to both the directions of the electron's velocity and the magnetic field.
The direction of the force exerted on the electron can be found by using the right-hand rule:
- Index finger: direction of the velocity of the electron --> towards the east
- Middle finger: direction of the magnetic field --> downward
- Thumb: direction of the force on a positive particle --> towards the north
However, the electron is a negatively charged particle, so we must reverse the direction of the force: therefore, the force exerted on the electron is towards the south.