Answer:
6.32 m/s
Explanation:
KE = 1/2 m v^2
sqrt (2 * KE /m) = v = 6.32 m/s
140 is the velocity because you need to multiply 40×2.5
Do both cars leave the starting line at the same time ? That's kind of important. I'll assume that they both start out at the same time, and now I'll proceed to answer the question that I have invented.
-- Car B moves 4 m/s faster than Car A .
-- So Car-A's lead shrinks by 4 meters every second after they start.
-- It takes (10/4) = 2.5 seconds for Car-A's lead to shrink to zero.
-- So Car-B overtakes Car-A <em>2.5 seconds</em> after they start.
The velocity of an object determines if it is moving. If the velocity is zero, it is not moving. If it has a positive velocity, then it is moving forward. If it has a negative velocity, then it is moving backwards.
B. Reversing the current direction will cause the force deflecting the
wire to be perpendicular to the magnetic field but in the opposite
direction.