Name: ____________________________________________
Section #_________ TA:______________
Physics 201
Fall 2009
Exam 1
September 29, 2009
Acceleration due to earth’s gravity g=9.8 m/s2
1. The density of seawater was measured to be 1.07 g/cm3. This density in SI units is
A) l.07 × 10–3 kg/m3
B) (1/1.07) × 103 kg/m3
C) 1.07 × 103 kg
D) 1.07 × 10–3 kg
E) 1.07 × 103 kg/m3
2. To convert a quantity from km/h to m/s, you must
A) multiply by 1000 and divide by 60.
B) multiply by 1000 and divide by 3600.
C) multiply by 60 and divide by 1000.
D) multiply by 3600 and divide by 1000.
E) None of these is correct.
3. If x and t represent distance and time, respectively, the C in x = 1/2Ct 2 must
A) have the dimensions ML/T 2.
B) have the dimensions M.
C) have the dimensions L/T 2.
D) have the dimensions L2/T 2.
E) be dimensionless.
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Name: ____________________________________________
4. In Newton's Law of Gravity the universal gravitational constant G = Fr2/m1m2, where
F is the gravitational force between the two masses, m1 and m2, and r is the distance
between them. What are the dimensions of G?
A) L2M–1T 2
B) L3M–1T –2
C) L2M–2T –2
D) L3M–1T 2
E) L–3M1T 3
5. The equation for the position of a train starting at x=0 as a function of time is given by
x(t) = at2/2 + bt3. The dimensions of b are:
-3
A) T
B) LT-3
C) LT-2
D) LT-1
E) L-1T-1
6.
A car proceeding due south at 60 km/h
traveling due west at 80 km/h
makes a right turn, after which it is
. What is its change in velocity
A) 100 km/h 37º north of west
B) 100 km/h 37º south of west
C) 20 km/h west
D) 20 km/h 37º north of west
E) 20 km/h 37º south of west
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?
Name: ____________________________________________
7. You drive for 30 min at 100 km/h and then stop for 15 min. You then drive for 45 min
at 80 km/h. Your average speed for the entire trip is
A) 73 km/h.
B) 83 km/h.
C) 88 km/h.
D) 90 km/h.
E) 97 km/h.
8.
The graph shows the velocity of a particle as a function of time. In the 12 s shown,
the particle travels
A) 0 m.
B) 1200 m.
C) 640 m.
D) 440 m.
E) 200 m.
9. An airplane flies 600 miles with a tail wind in 2.0 hrs. If it takes 3.0 hrs to cover the
same distance against the headwind, then what is the speed of the plane in still air?
A) 270 mph
B) 300 mph
C) 240 mph
D) 330 mph
E) 250 mph
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Name: ____________________________________________
10. An object is moving in a straight line. At t = 0, its speed is 5.0 m/s. From t = 0 to t =
4.0 s, its acceleration is 2.5 m/s2. From t = 4.0 s to t = 11.0 s, its speed is constant.
The average speed over the entire time interval is
A) 9.5 m/s
B) 15 m/s
C) 13 m/s
D) 21 m/s
E) 8.2 m/s
11. A projectile is fired vertically upward with a speed of 62 m/s. In the absence of air
resistance, the maximum height the projectile attains is
A) 25 km
B) 98 m
C) 200 m
D) 19 km
E) 3 m
12.
Two of the graphs shown are INCORRECT for a particle undergoing onedimensional motion with constant acceleration. They are
A) 1 and 2
B) 2 and 3
C) 3 and 4
D) 4 and 5
E) 1 and 5
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Name: ____________________________________________
13. A sandbag is released from a rising air balloon and hits the ground 7 seconds later.
From what height was the sandbag dropped from if at the moment of release the
balloon was traveling upward at 3 m/s.
A) 219 m
B) 240 m
C) 459 m
D) 261 m
E) 55 m
14. A projectile is ejected from a 25-m high tower with a velocity of 40 m/s at an angle of
30 degrees to the horizontal first on Earth and then on Mars. What is the ratio of the
time taken to hit the ground on Mars compared to Earth? (Assume gMars = 0.38gEarth)
A) 2.3
B) 2.9
C) 0.38
D) 6.9
E) 1.0
15. The relationship between the velocity of a body moving along the x axis and time is
given by v = 2t3 + 2t, where the units are SI units. The total distance the body
travels between the times t = 2 s and t = 4 s is
A) 132 m
B) 144 m
C) 136 m
D) 120 m
E) 156 m
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Name: ____________________________________________
16. The acceleration of a vehicle is given by a(t) = At where A is a constant. Its velocity
as a function of time is (vo is a constant)
A)
B) v(t) = At2 + vo
C) v(t) = At + vo
D)
E) None of these is correct.
17. A particle has an initial velocity of 4.8 m/s toward the south and a final velocity of
7.1 m/s toward the east. The particle was subject to a constant acceleration for 0.25
s. The magnitude and the direction of the acceleration must have been
A) 8.6 m/s2 at 34.1º north of east
B) 260 m/s2 at 34.1º south of east
C) 34 m/s2 at 34.1º north of east
D) 34 m/s2 at 34.1º south of east
E) 8.6 m/s2 at 34.1º south of east
18. A pilot wants the heading of an airplane to be 45º east of north. The wind is from the
west at 32 km/h, and the speed of the airplane through the air is 320 km/h. The pilot
should maintain a heading of approximately
A) 15º (measuring clockwise from north)
B) 49º (measuring clockwise from north)
C) 41º (measuring clockwise from north)
D) 4º (measuring clockwise from north)
E) 131º (measuring clockwise from north)
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Name: ____________________________________________
19. A skier leaves a ski jump with a horizontal velocity of 29.4 m/s. Ignoring air
resistance, the instant before she lands three seconds later, her speed is:
A) zero
B) 29.4 m/s
C) 41.6 m/s
D) 50.9 m/s
E) 88.2 m/s
20. A squirrel jumps from a tree limb onto a birdfeeder. The tree limb is 4.5 m above the
ground and the top of the birdfeeder is 1.5 m above the ground. If the squirrel jumps
horizontally with a velocity of 2.5 m/s then how far away in the horizontal direction
can the bird feeder be for the squirrel to just make it onto the top of the feeder.
A) 3.6 m
B) 2.0 m
C) 2.4 m
D) 1.5 m
E) 1.4 m
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