Statics — Quiz 4

Questions in this quiz (10)

1. A box rests on the bed of a truck. The coefficient of static friction between the box and the truck bed is $$0.35$$. Determine the maximum deceleration the truck can undergo before the box begins to slide. Assume $$g=9.81\ m/s^2$$.

   • $$3.43\ m/s^2$$
   • $$1.72\ m/s^2$$
   • $$0.35\ m/s^2$$
   • $$2.94\ m/s^2$$

2. A crate is placed on a horizontal conveyor belt. The coefficient of static friction between the crate and the belt is $$0.45$$. Determine the maximum acceleration of the belt before the crate begins to slip. Assume $$g=9.81\ m/s^2$$.

   • $$2.21\ m/s^2$$
   • $$4.41\ m/s^2$$
   • $$3.16\ m/s^2$$
   • $$1.98\ m/s^2$$

3. A package rests on a flat truck bed. The coefficient of static friction between the package and the surface is $$0.30$$. Determine the maximum deceleration of the truck that will prevent slipping. Assume $$g=9.81\ m/s^2$$.

   • $$2.94\ m/s^2$$
   • $$1.47\ m/s^2$$
   • $$3.92\ m/s^2$$
   • $$0.98\ m/s^2$$

4. A crate weighing $$60\ N$$ is held in place by three ropes connected at a joint. One rope is vertical and supports the crate, one rope is horizontal to the right with tension $$T_2$$, and the third rope goes up to the left making an angle of $$53^\circ$$ with the horizontal, with tension $$T_1$$. If the system is in equilibrium, determine $$T_1$$ and $$T_2$$.

   • $$T_1=60.00\ N,\ T_2=45.24\ N$$
   • $$T_1=75.13\ N,\ T_2=45.24\ N$$
   • $$T_1=75.16\ N,\ T_2=60.00\ N$$
   • $$T_1=45.24\ N,\ T_2=75.16\ N$$

5. A wall-mounted cabinet weighing $$250\ N$$ is supported by hinges $$A$$ and $$B$$ attached to a vertical wall. The cabinet is $$4\ m$$ tall and $$2.5\ m$$ wide. The hinges are vertically separated by $$2\ m$$. Determine the horizontal reaction at hinge $$A$$.

   • $$125\ N$$ $$\leftarrow$$
   • $$156\ N$$ $$\leftarrow$$
   • $$160\ N$$ $$\leftarrow$$
   • $$200\ N$$ $$\leftarrow$$

6. Two rescue boats $$A$$ and $$B$$ are towing a disabled ship as shown in the figure. The tension in rope $$B$$ is three-fourths of the tension in rope $$A$$. If rope $$A$$ makes an angle of $$25^\circ$$ with the $$x$$-axis, determine the angle that rope $$B$$ must make so the ship moves along the $$x$$-axis.

   • $$30^\circ$$
   • $$34^\circ$$
   • $$42^\circ$$
   • $$55^\circ$$

7. A vertical mast is supported by two guy wires as shown in the figure. The tension in cable $$AB$$ is $$120\ N$$. If the mast is in equilibrium, determine the tension in cable $$AC$$ in $$N$$.

   • $$95$$
   • $$120$$
   • $$140$$
   • $$165$$

8. A vertical mast is supported by two guy wires as shown in the figure. The tension in cable $$AB$$ is $$120\ N$$. If the mast is in equilibrium, determine the tension in cable $$AC$$ $$\left(N\right)$$.

   • $$89$$
   • $$120$$
   • $$140$$
   • $$165$$

9. A $$2$$-member truss is supporting a $$5\ kN$$ load as shown in the figure. Determine the member forces $$\left(kN\right)$$. Member $$BO$$ makes $$55^\circ$$ with the horizontal. Member $$AO$$ makes $$35^\circ$$ with the horizontal. The applied load of $$5\ kN$$ acts at $$40^\circ$$ below the horizontal. Which of the following is true?

   • $$4.50$$ compression , $$1.29$$ tension
   • $$1.29$$ compression , $$4.50$$ tension
   • $$4.50$$ tension , $$1.29$$ compression
   • $$6.20$$ compression , $$2.10$$ tension

10. A roof-top unit being hung down from a crane requires a horizontal pull to be placed at its specified location, as shown in the figure. If the unit weighs $$1200\ lb$$, the required pull $$T$$ $$\left(lb\right)$$ is most nearly:

    • $$37.26$$
    • $$360$$
    • $$1200$$
    • $$11500$$