PROBLEM 14.110 (Continued)
PROBLEM 14.111
Car A of mass 1800 kg and car B of mass 1700 kg
are at rest on a 20-Mg flatcar which is also at rest.
Cars A and B then accelerate and quickly reach
constant speeds relative to the flatcar of 2.35 m/s
and 1.175 m/s, respectively, before decelerating to
a stop at the opposite end of the flatcar. Neglecting
friction and rolling resistance, determine the
velocity of the flatcar when the cars are moving at
constant speeds.
PROBLEM 14.112
The nozzle shown discharges water at the rate of 200 gal/min. Knowing
that at both B and C the stream of water moves with a velocity of
magnitude 100 ft/s, and neglecting the weight of the vane, determine the
force-couple system that must be applied at A to hold the vane in place
3
(1 ft 7.48 gal).
PROBLEM 14.112 (Continued)
PROBLEM 14.113
An airplane with weight W and total wing
span b flies horizontally at a constant speed v.
Use the airplane as a reference frame; that is,
consider the airplane to be motionless and the
air to flow past it with speed v. Suppose that a
cylinder of air with diameter b is deflected
downward by the wing (the cross section of
the cylinder is the dashed circle in in the
figure). Show that the angle through which the
cylinder stream is deflected (called the
downwash angle) is determined by the
formula 4/ where
is the
mass density of the air.
PROBLEM 14.114
The final component of a conveyor system
receives sand at a rate of 100 kg/s at A and
discharges it at B. The sand is moving horizontally
at A and B with a velocity of magnitude
4.5
AB
vv m/s. Knowing that the combined
weight of the component and of the sand it
supports is 4W
kN, determine the reactions at
C and D.
PROBLEM 14.115
A garden sprinkler has four rotating arms, each of which
consists of two horizontal straight sections of pipe forming
an angle of 120° with each other. Each arm discharges
water at a rate of 20 L/min with a velocity of 18 m/s
relative to the arm. Knowing that the friction between the
moving and stationary parts of the sprinkler is equivalent to
a couple of magnitude
0.375 N m,M
determine the
constant rate at which the sprinkler rotates.
PROBLEM 14.116
A chain of length l and mass m falls through a small hole in a
plate. Initially, when y is very small, the chain is at rest. In
each case shown, determine (a) the acceleration of the first
link A as a function of y, (b) the velocity of the chain as the
last link passes through the hole. In case 1, assume that the
individual links are at rest until they fall through the hole; in
case 2, assume that at any instant all links have the same
speed. Ignore the effect of friction.
PROBLEM 14.116 (Continued)