Page 336 - Dynamics of Mechanical Systems

0593_C09_fm Page 317 Monday, May 6, 2002 2:50 PM

Principles of Impulse and Momentum 317

O

h

m
FIGURE P9.7.9
A bullet fired into a hanging bar. V

n
2
C
B n 1
n
3
G
10 m/sec
4 m
O
FIGURE P9.7.11
A rectangular plate striking a fixed 3 m D
ledge. A
P9.7.12: See Problem P9.7.11. Determine the velocities of points A, B, and C and the mass
center G of the plate just after impact.
P9.7.13: See Problem P9.7.10. In Problem 9.7.10 find the distance h so that the bullet strikes
the bar at the center of percussion so that there is no horizontal reaction at the pin at O.
Repeat Problem 9.7.10 using this value of h instead of 0.8 m.
P9.7.14: Consider again the pin-connected double bar of Figure 9.8.7 and shown again in
Figure P9.7.14. Let the bars each have length 1.0 m and mass 0.5 kg. Let the impulse of
the force P be 150 Nm. Determine the velocity of end O and the angular velocities of the
bars just after impact.

1 m Q 1 m O

FIGURE P9.7.14 P
Pin-connected bars struck at one end.
P9.7.15: Repeat the analysis of Example 9.8.4 if the bars are no longer identical but instead
have lengths and and masses m and m where the masses are proportional to the
1
2
2
1
lengths.
P9.7.16: An automobile wheel and tire W weighing 50 lb with diameter 24 in. and axial
radius of gyration 7 in. is rolling at 15 mph toward a 6-in. curb. Find the angular velocity
of W immediately after impact with the curb.
Section 9.10 Impact: Coefficient of Restitution
P9.10.1: A car A traveling at 20 mph strikes the rear of a car B which is at rest as in Figure
P9.10.1. Let the weights of A and B be 3220 lb and 2800 lb, respectively. Determine the
speeds of A and B immediately after collision under the following assumptions.