1) p. 390 #7
A spring and a block are arranged to oscillate
(1) on a frictionless horizontal surface as in Fig.,
(2) on a frictionless slope of 45˚ (with the block on the lower end of the spring), and
(3) vertically while hanging from a ceiling.
Rank the arrangements according to the frequency of oscillation, greatest first.
a) 1,2,3 b) 3,2,1 c) the same
2) p. 342 #11
In Fig two spheres of mass m and a third sphere of Mass M form an equilateral triangle, and a fourth sphere of mass _ is at the center of the triangle. The net gravitation force on _ from the three other spheres is zero.
What is M in terms of m.
a) m b) 2m c) m
√
2
3) p. 288 #3b
A cannonball rolls down an incline without sliding. If the roll is now repeated with an incline that is less steep but of the same height as the first incline, is the ball’s kinetic energy at the bottom a) grater than b) less than c) the same as previously?
4) p. 207 #3E
What are the coordinates of the center of mass of the three-particle system shown in Fig a) x cm
=1.0, y cm
=1.0
b) x cm
=1.1, y cm
=1.3
c) x cm
=1.5, y cm
=1.5
5) p. 259 #10
Solids with identical masses are shown in cross section in fig The cross section have equal wit at the widest part and equal heights (but not necessary equal thickness). Which one has the greatest rotational inertia about an axis through its center of massand perpendicular to its cross section?
a) Hoop b) Cube c) Cylinder
6) p. 105 #63
A 100kg crate is pushed at constant speed up the frictionless 30˚ ramp shown in Fig. What horisontal force
F is required?
a) F=1000N b) F=566N c) F=500N
7) p. 76 #48
A certain airplane has a speed of 180 mi/h and is diving at an angle of 30˚ below the horizontal when a radar decoy is released (See Fig).) The horizontal distance between the released point and the point where the decoy strikes the ground is 2300 ft.

Question 1: How long was the decoy in the air? Or question 2: How high was the plain when the decoy was released?
Please check my typing.
Thank you
Anatoli