6) A point on a wheel of radius 40 cm that is
rotating at a constant 5.0 revolutions per
second is located 0.20 m from the axis of
rotation. What is the acceleration of that
point due to the spin of the wheel?
A) 0.050 m/s2
B) 1.4 m/s2
C) 48 m/s2
D) 200 m/s2
E) 0.00 m/s2
Answer: D
8) The maximum acceleration a pilot can
stand without blacking out is about 7.0 g. In
an endurance test for a jet plane's pilot, what
is the maximum speed he can tolerate if he
is spun in a horizontal circle of diameter 85
m?
Answer: 54 m/s
14) The curved section of a horizontal
highway is a circular unbanked arc of radius
740 m. If the coefficient of static friction
between this roadway and typical tires is
0.40, what would be the maximum safe
driving speed for this horizontal curved
section of highway?
A) 54 m/s
B) 52 m/s
C) 50 m/s
D) 48 m/s
E) 46 m/s
Answer: A
15) A 250-kg motorcycle goes around an
unbanked turn of radius 13.7 m at a steady
96.5 km/h. What is the magnitude of the net
force on the motorcycle?
A) 719 N
B) 2.95 × 103 N
C) 1.31 × 104 N
D) 4.31 × 104 N
Answer: C
16) A 0.50-kg toy is attached to the end of a
1.0-m very light string. The toy is whirled
in a horizontal circular path on a frictionless
tabletop. If the maximum tension that the
string can withstand without breaking is 350
N. What is the maximum speed the mass
can have without breaking the string?
A) 700 m/s
B) 26 m/s
C) 19 m/s
D) 13 m/s
Answer: B
21) Two planets have the same surface
gravity, but planet B has twice the radius of
planet A. If planet A has mass m, what is
the mass of planet B?
A) m/
B) m
C) m
D) 4m
E) m/4
Answer: D
24) The reason an astronaut in an earth
satellite feels weightless is that
A) the astronaut is beyond the range of the
earth's gravity.
B) the astronaut is falling.
C) the astronaut is at a point in space where
the effects of the moon's gravity and the
earth's gravity cancel.
D) this is a psychological effect associated
with rapid motion.
E) the astronaut's acceleration is zero.
Answer: B
28) Halley's Comet is in a highly elliptical
orbit around the sun. Therefore the orbital
speed of Halley's Comet, while traveling
around the sun,
A) is constant.
B) increases as it nears the Sun.
C) decreases as it nears the Sun.
D) is zero at two points in the orbit.
Answer: B
29) Let the orbital radius of a planet be R
and let the orbital period of the planet be T.
What quantity is constant for all planets
orbiting the sun, assuming circular orbits?
A) T/R
B) T/R2
C) T2/R3
D) T3/R2
E) T2/R
Answer: C
4) A disk-shaped space station 125 m in
diameter spins at a uniform rate about an
axis through its center and perpendicular to
the plane of the disk. If the acceleration of a
point on the rim of the disk is to be equal to
g, how long does it take for the station to
make one revolution? Use g = 9.8 m/s2.
Answer: 16 s
33) A 600-kg car is going around a banked
curve with a radius of 110 m at a steady
speed of 24.5 m/s. What is the appropriate
banking angle so that the car stays on its
path without the assistance of friction?
A) 29.1°
B) 13.5°
C) 33.8°
D) 56.2°
E) 60.9°
Answer: A
36) Two horizontal curves on a bobsled run
are banked at the same angle, but one has
twice the radius of the other. The safe speed
(for which no friction is needed to stay on
the run) for the smaller radius curve is v.
What is the safe speed on the larger-radius
curve?
A) v /
B) 2v
C) v
D) v/2
Answer: C
39) A highway curve of radius 80 m is
banked at 45°. Suppose that an ice storm
hits, and the curve is effectively frictionless.
What is the speed with which to take the
curve without tending to slide either up or
down the surface of the road?
A) 9.4 m/s
B) 28 m/s
C) 780 m/s
D) The curve cannot be taken safely at any
speed.
Answer: B
48) A spaceship with a mass of 2.8 × 106 kg
is traveling toward two spherical asteroids,
each with a mass of 5.0 × 1016 kg, that are
40 km apart center-to-center. Its path is
perpendicular to the line joining the
asteroids and is aimed at the midpoint of that
line. What is the net gravitational force
exerted by the asteroids on the spaceship
when the spaceship is 30 km away from that
midpoint? (G = 6.67 × 10-11 N ∙ m2/kg2)
A) 12,000 N
B) 8,000 N
C) 16,000 N
D) 6,200 N
E) 18,000 N
Answer: A
49) Three identical 50-kg balls are held at
the corners of an equilateral triangle, 30 cm
on each side. If one of the balls is released,
what is the magnitude of its initial
acceleration if the only forces acting on it
are the gravitational forces due to the other
two masses? (G = 6.67 × 10-11 N ∙ m2/kg2)
A) 3.7 × 10-8 m/s2
B) 2.5 × 10-8 m/s2
C) 1.9 × 10-8 m/s2
D) 4.2 × 10-8 m/s2
E) 6.4 × 10-8 m/s2
Answer: E
56) What would be the weight of a 59.1-kg
astronaut on a planet twice as massive as
Earth and having twice Earth's radius?
A) 580 N
B) 290 N
C) 1160 N
D) 118 N
E) 1200 N
Answer: B
60) The radius of the earth is R. At what
distance above the earth's surface will the
acceleration of gravity be 4.9 m/s2?
A) 0.41 R
B) 0.50 R
C) 1.00 R
D) 1.41 R
E) 0.25 R
Answer: A
72) Find the orbital speed of an ice cube in
the rings of Saturn. The mass of Saturn is
5.68 x 1026 kg, and use an orbital radius of
1.00 x 105 km. (G = 6.67 × 10-11 N ∙
m2/kg2)
A) 19.5 km/s
B) 27.5 km/s
C) 13.8 km/s
D) 9.40 km/s
Answer: A