PROBLEM 13.25
Four 3–kg packages are held in place by friction on a conveyor
which is disengaged from its drive motor. When the system is
released from rest, package 1 leaves the belt at A just as
package 4 comes onto the inclined portion of the belt at B.
Determine (a) the velocity of package 2 as it leaves the belt at
A, (b) the velocity of package 3 as it leaves the belt at A.
Neglect the mass of the belt and rollers.
PROBLEM 13.25 (Continued)
PROBLEM 13.26
A 3–kg block rests on top of a 2–kg block supported by, but not attached to, a spring of
constant 40 N/m. The upper block is suddenly removed. Determine (a) the maximum
speed reached by the 2–kg block, (b) the maximum height reached by the 2-kg block.
PROBLEM 13.26 (Continued)
PROBLEM 13.27
Solve Problem 13.26, assuming that the 2-kg block is attached to the spring.
PROBLEM 13.26 A 3–kg block rests on top of a 2–kg block supported by, but not
attached to, a spring of constant 40 N/m. The upper block is suddenly removed.
Determine (a) the maximum speed reached by the 2-kg block, (b) the maximum height
reached by the 2-kg block.
PROBLEM 13.27 (Continued)
PROBLEM 13.28
People with mobility impairments can gain great health
and social benefits from participating in different
recreational activities. You are tasked with designing an
adaptive spring–powered shuffleboard attachment that
can be utilized by people who use wheelchairs.
Knowing that the coefficient of kinetic friction between
the 15 ounce puck A and the wooden surface is 0.3, the
maximum spring displacement you desire is 6 inches,
and that you want the puck to travel at least 30 ft/s,
determine (a) the spring constant k, (b) how far the
athlete should pull back the spring to make the puck
come to rest after 34 ft.
PROBLEM 13.29
A 7.5–lb collar is released from rest in the position shown, slides
down the inclined rod, and compresses the spring. The direction of
motion is reversed and the collar slides up the rod. Knowing that
the maximum deflection of the spring is 5 in., determine (a) the
coefficient of kinetic friction between the collar and the rod, (b) the
maximum speed of the collar.
PROBLEM 13.30
A 10–kg block is attached to spring A and connected to spring B by a cord and
pulley. The block is held in the position shown with both springs unstretched when
the support is removed and the block is released with no initial velocity. Knowing
that the constant of each spring is 2 kN/m, determine (a) the velocity of the block
after it has moved down 50 mm, (b) the maximum velocity achieved by the block.
PROBLEM 13.30 (Continued)