Question

10 at the top of the loop, a roller coaster car feels 520 n downward from gravity. the track pushes upward with 515 n, and air resistance joins the rebellion with 5 n upward. find the net force and direction at that moment

Explanation:

Step1: Define downward as positive

Let the gravitational force $F_g = 520N$, the normal force from the track $F_n=- 515N$ (negative as it is upward), and the air - resistance force $F_{air}=-5N$ (negative as it is upward).

Step2: Calculate the net force

The net force $F_{net}$ is the sum of all forces. Using the formula $F_{net}=F_g + F_n+F_{air}$. Substitute the values: $F_{net}=520+( - 515)+(-5)$.
$F_{net}=520 - 515-5$.
$F_{net}=0N$.

Answer:

The net force is $0N$.