Which of the following statements is true about the ion channel controlled by the nicotinic receptor?

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 16 in. and d = 23 in., three uncoated No. 8 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 3 Grade 40 stirrups located every 6 in. along the span. Assume 5,000-psi normal-weight concrete and a clear cover of 2 in.

Compute φVn for the cross section shown. Assume f’c = 6,000 psi, fyt = 60,000 psi, b1 = 28 in., b2 = 13 in., d1 = 4 in., d2 = 18 in., and that there are three No. 7 longitudinal tension bars and No. 4 stirrups at 7 in. o.c.

A simply-supported beam has a 5 kip/ft uniformly-distributed load over the entire 10-ft span. What is the magnitude of the maximum shear force in the beam?

Use ACI 318-14 Table 25.4.2.2 to determine the development length for the straight tension bars (no hooks) in a rectangular beam with b = 17 in. and d = 20 in., five galvanized No. 9 Grade 60 bars placed in the bottom of the beam, and No. 4 Grade 60 stirrups located every 8 in. along the span. Assume 7,000-psi lightweight concrete and a clear cover of 1.75 in.

Determine the epoxy modification factor, ψe, for a rectangular beam with b = 17 in. and d = 21 in., five uncoated No. 8 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 4 Grade 40 stirrups located every 6 in. along the span. Assume 5,000-psi normal-weight concrete and a clear cover of 2 in.

For a beam with stirrup hooks, the free end of the bar must extend at least _____ from the hook. Assume b1 = 39 in., b2 = 16 in., d1 = 4 in., d2 = 29 in., and that there are three No. 9 longitudinal tension bars and No. 4 stirrups at 11 in. o.c. The stirrup hooks are 90°.

At a point subjected to plane stress, the stresses are σx = 25 ksi, σy = 5 ksi, and τxy = –20 ksi. Determine the angle θp corresponding to the orientation of the principal planes at the point.

A continuous beam’s flexural reinforcement must extend at least _____ from the point where it is no longer needed to resist tension. Assume f’c = 4,000 psi, fyt = 40,000 psi, b1 = 28 in., b2 = 10 in., d1 = 4 in., d2 = 19 in., and that there are three No. 7 longitudinal tension bars and No. 5 stirrups at 12 in. o.c. The stirrup hooks are 90°.

A continuous beam’s flexural reinforcement must extend at least _____ from the point where it is no longer needed to resist tension. Assume f’c = 4,000 psi, fyt = 40,000 psi, b1 = 28 in., b2 = 15 in., d = 23 in., h1 = 6 in., h2 = 13 in., h3 = 9 in., and t = 6 in. There are four No. 8 longitudinal tension bars and No. 3 stirrups at 9 in. o.c.