6. Intro to Forces (Dynamics)

In the context of forces in connected systems of objects, what is the primary significance of using roller connections instead of pinned connections?

A $5000\mathrm{kg}$ truck is parked on a $7.0°$ slope. What is the magnitude of the friction force acting on the truck?

Two blocks of masses $m_1$ and $m_2$ are connected by a massless rope and pulled horizontally on a frictionless surface by a force $F$ applied to $m_2$. What is the tension in the rope between the blocks?

Four masses are connected by massless, rigid rods to form a system as shown in Figure 1. If the system is suspended from one of the masses and hangs in equilibrium, which of the following statements about the tension in the rods is correct?

In a loaded truss, certain members carry no force under specific loading conditions. Which of the following statements correctly identifies a zero-force member in a truss where three members form a joint and two of them are collinear with no external load or support at the joint?

A uniform horizontal beam is supported at its ends by two vertical rods, AB and CD. If the beam is in static equilibrium and a downward force $F$ is applied at a point closer to support AB than to CD, which statement correctly describes the forces in rods AB and CD?

In a suspension bridge, the main cable attaches to the left bridge support at a height of $h$ ft above the roadway. If the tension in the cable at this point is $T$ and the mass of the bridge deck is $m$, which of the following expressions correctly gives the vertical component of the force exerted by the cable on the support if the cable makes an angle $\theta$ with the horizontal?

A cylindrical cable of negligible mass is suspended vertically from the ceiling, and a weight of mass $m$ hangs from its lower end. If the cable is in equilibrium, what is the tension in the cable at a point halfway between the ceiling and the weight?

A horizontal beam is constructed by nailing together three boards as shown in Figure 1. If the total mass of the beam is $m$ and it is supported at both ends, what is the magnitude of the upward force exerted by each support when the beam is at rest and no additional loads are applied?

A rigid pipe is supported by a pin at point A and an A-36 steel guy wire BD. If a downward force of $5 \mathrm{kN}$ is applied at the end of the pipe, which of the following best describes the role of the guy wire BD in the system?

Three people pull simultaneously on a stubborn donkey with forces of $100$ N, $120$ N, and $80$ N, all in the same direction. What is the magnitude of the net force acting on the donkey?

A uniform beam is constructed from three identical boards fastened together to form a single rigid object. If the total mass of the beam is $M$ and its length is $L$, what is the magnitude of the gravitational force acting on the beam when it is suspended horizontally by two supports at its ends?

Three masses are connected in a straight line by massless, rigid rods and placed on a frictionless horizontal surface. If a force $F$ is applied to the leftmost mass, what is the tension in the rod between the middle and rightmost mass?