Question

The free-body diagrams of four objects are shown.

Which object has a net force of –5 N down?

A. w
B. x
C. y
D. z

Answer 1

Answer:

B. x

Explanation:

Let's calculate the net force for each object:

W) The horizontal net force is zero, because $F_p+F_f = 10 N-10 N=0$. The vertical net force is instead $F_N+F_g=20 N-15 N=+5 N$ upward, so this is not the right option

X) The horizontal net force is zero, because $F_p+F_f = 15 N-15 N=0$. The vertical net force is instead $F_N+F_g=20 N-25 N=-5 N$ downward, so this is the correct choice

Y) The horizontal net force is $F_p+F_f = 10 N-15 N=-5 N$. The vertical net force is instead zero, because $F_N+F_g=10 N-10 N=0 N$, so this is not the right option

Z) he horizontal net force is $F_p+F_f = 20 N-10 N=10$. The vertical net force is instead zero, because $F_N+F_g=15 N-15 N=0 N$, so this is not the right option

Answer 2

Answer:

it's actually W

Explanation:

Took the test on e2020