Answer: The change in velocity is 20mph
Explanation: The change in velocity is the difference between the final velocity and the initial velocity.
The initial velocity is 0 and the final velocity is 20mph.
Using the formula dV=Vf-Vi
dV=20-0
dV=20mph North
Answer: a) 127 eV; b) there is no change of kinetic energy.
Explanation: In order to explain this problem we have to use the change of potentail energy ( conservative field) is equal to changes in kinetic energy. So for the proton ther move to lower potential then they gain kinetic energy from the electric field. This means the electric force do work in this trayectory and then the protons increased changes its speed.
If we replace the proton by a electron we have a very different situaction, the electrons are located in a lower potental then they can not move to higher potential if any external force does work on the system.
In resumem, the electrons do not move from a point with V=87 to other point with V=-40 V. The electric force point to high potential so the electrons can not move to lower potential region (V=-40V).
Upstream speed = S - 1
Downstream speed = S + 1
Average speed = total distance / total time
Average speed = (S - 1) + (S + 1) / 2
= S
S = 6 miles / 4 hours
S = 1.5 miles per hour
Answer:
C) Plastic
Explanation:
Copper, silver, and gold all conduct electricity. Therefore, the material that would provide the most resistance for electricity would be plastic.