Page 367 - Dynamics of Mechanical Systems

0593_C10_fm Page 348 Monday, May 6, 2002 2:57 PM

348 Dynamics of Mechanical Systems

θ
1

θ
2

FIGURE P10.5.5 θ 3
Triple-rod pendulum.
gyration are 10 and 7 in., respectively, determine the kinetic energy of one of the rear
wheels for the spinning vehicle.

Sections 10.6 to 10.9: Work–Energy Principles and Applications
P10.6.1: A ball is thrown vertically upward with a speed of 12 m/sec. Determine the
maximum height h reached by the ball.
P10.6.2: An object is dropped from a window which is 45 ft above the ground. What is
the speed of the object when it strikes the ground?
P10.6.3: See Problem P10.6.1. What is the speed of the ball when it is 3 m above the thrower.
P10.6.4: A water faucet is dripping slowly. When a drop has fallen 1 ft, a second drop
appears. What are the speeds of the drops when the first drop has fallen 3 ft? What is the
separation between the drops at that time?
P10.6.5: A simple pendulum consists of a light string of length 3 ft and a concentrated
mass P weighing 5 lb at the end as in Figure P10.6.5. Suppose the pendulum is displaced
through an angle θ of 60° and released from rest. What is the speed of P when θ is (a) 45°,
(b) 30°, and (c) 0°?

O
θ
(3 ft)

FIGURE P10.6.5
A simple pendulum. P (5 lb)

P10.6.6: See Problem P10.6.5. Suppose P has a speed of 7.5 ft/sec when θ is 0. What is the
maximum angle reached by P?
P10.6.7: See Problems 10.6.5 and P10.6.6. What is the minimum speed v of P when θ is 0
so that the pendulum will make a complete loop without the string becoming slack even
in the topmost position (θ = 180°)?
P10.6.8: Repeat Problems P10.6.5 to 10.6.7 if the mass of P is 10 lb instead of 5 lb.
P10.6.9: Repeat Problems P10.6.5 to 10.6.7 if the length of the pendulum is 4 ft.