A bead at C can move along the straight rod AB. An elastic cord CD is under tension and is attached to
the bead.
b
a
y
e
D
d
Ο
B
f
C
C
X
2
Point A has coordinates (c, 0, f). Point B has coordinates (0, b, a). Point D has coordinates (e, d, 0).
Distances in the figure are a = 3.5 cm, b = 4.2 cm, c = 17.8 cm, d = 16.9 cm, e = 14.7 cm, and f =
15.9 cm.
Find the unit vector that points along the rod in the direction from A to B.
UAB = -0.806 ✔+ 0.190
✔+-0.561
k
If the distance from B to C is 11.1 cm, find the unit vector that points along the cord in the direction from
C to D.
UCD = 0.909 x + 0.406
x + 0.104
xk
By computing the dot product UAB UCD, determine the angle ∠BCD.
LBCD = 136
X