Hello There!
Let's first talk about <em>"What Is Friction"</em>
<u>Friction is a force that pulls when two object touch each-other. Friction happens because the molecules on one surface interlock with the molecules on another surface.</u>
<u></u>
Now, let's get back to our original question "What Effect Does Friction Have On A Roller Coaster"
On a roller coaster, friction is a force that opposes motion and significantly slows the cars as they move on the track.
Answer:
Magnetic force, 
Explanation:
It is given that,
Magnetic field, B = 2 T
Velocity of the proton, v = 300 m/s
Charge on the proton, 
The magnetic field is oriented perpendicular to the proton’s velocity. The magnetic force on the charged particle is given by :
The magnetic field is oriented perpendicular to the proton’s velocity, 
So, the magnitude of the force that the proton experiences while it moves through the magnetic field is 
. Hence, this is the required solution.
Answer: only the third option. [Vector A] dot [vector B + vector C]
The dot between the vectors mean that the operation to perform is the "scalar product", alson known as "dot product".
This operation is only defined between two vectors, not one scalar and one vector.
When you perform, in the first option, the dot product of any ot the first and the second vectors you get a scalar, then you cannot make the dot product of this result with the third vector.
For the second option, when you perform the dot product of vectar B with vector C you get a scalar, then you cannot make the dot product ot this result with the vector A.
The third option indicates that you sum the vectors B and C, whose result is a vector and later you make the dot product of this resulting vector with the vector A. Operation valid.
The fourth option indicates the dot product of a scalar with the vector A, which we already explained that is not defined.
<span>The electrons need to migrate from a region of lower electric potential to a region of higher electric potential. This flow of electrons is known as electron current (which is contrary to the widely-accepted perspective of conventional current).</span>
The material in which a wave travels is called a medium. Hope this helps!
