Abike is moving north when the rider applies the brakes. in which direction does the frictional force act between the ground and the bike's wheels? a.north b.south c.upward d.downward

Since the biker is moving in the north direction. So, its velocity is in the north direction. Now, when he applies the brake, it slows down due to friction. Since, the velocity is decreasing. Hence, the acceleration direction is in the opposite direction and the direction opposite to the north is south. Hence, the frictional force is acting in the south direction.

So, the answer is B. South

Explanation:

For resistances in parallel we know that the overall resistance will be smaller in the value than any individual resistance. so, in this case we are concerned about = ⁺

where Rs is the series resistor and Rp is the parallel resistor.

so, R = 0.9M, roughly.

So, as the infernal resistance is very high as compared to the resistance conntected in parallel that is 100 Ω is not be used.