Question

use the following scenario to answer questions 1 - 4. a 25 kg cart is currently in dynamic equilibrium and is experiencing the forces seen in the diagram below: $f_n = +245.25n$, $f_a=-75n$, $f_f = ___n$, $f_g=-245.25n$. question 1 * 1 point 1. which of the following claims is supported by the presented information and the model? a. the cart is experiencing unbalanced forces. b. the force of friction ($f_f$) must be equal in magnitude to the force of gravity ($f_g$). c. the cart is currently at rest. d. the force of friction ($f_f$) must be equal in magnitude to the applied force ($f_a$).

Explanation:

Step1: Recall dynamic equilibrium concept

In dynamic equilibrium, the net force on an object is zero and the object is moving with a constant velocity. For horizontal forces, the sum of forces in the x - direction must be zero.

Step2: Analyze horizontal forces

The horizontal forces acting on the cart are the applied force $F_A=- 75N$ and the friction force $F_F$. Since the net force in the x - direction $F_{net,x}=0$ (due to dynamic equilibrium), we have $F_A + F_F=0$.

Step3: Solve for friction force

From $F_A + F_F=0$, we can express $F_F=-F_A$. Substituting $F_A = - 75N$, we get $F_F = 75N$. This means the magnitude of the friction force is equal to the magnitude of the applied force.

Answer:

D. The force of friction ($F_F$) must be equal in magnitude to the applied force ($F_A$).