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1.
1.
2.
2. Answer e
a. no, started at -1
b. no, initial velocity 2
c. no, a is 3 (double 1.5)
d. no, a constant
e. yes !
3.
Assume that a cart is on straight, level Rails. A motion detector is set up to record the motion of the cart in such a way that motion
away from the detector is chosen to be positive. (A) The cart remains at rest on the positive side of the motion detector for 1 second,
and then (B) starts moving away from the motion detector quickly, steadily speeding up over 2 seconds. Then (C) the cart continues
on at a constant speed for 2 seconds. Then (D) it stops abruptly, and (E) remains stopped for 1 second, before (F) moving towards
the detector, slowly, steadily speeding up over 2 seconds. Finally, (G) the cart continues on at a constant speed towards the detector
for 3 seconds. Which line in the following graph best shows the velocity of the cart ?
3. Answer D yellow dashed line
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Assume that a cart is on straight, level Rails. A motion detector is set up to record the motion of the cart in such a way that motion
away from the detector is chosen to be positive. (A) The cart remains at rest on the positive side of the motion detector for 1 second,
and then (B) starts moving away from the motion detector quickly, steadily speeding up over 2 seconds. Then (C) the cart continues
on at a constant speed for 2 seconds. Then (D) it stops abruptly, and (E) remains stopped for 1 second, before (F) moving towards
the detector, slowly, steadily speeding up over 2 seconds. Finally, (G) the cart continues on at a constant speed towards the detector
for 3 seconds. Which line in the following graph best shows the velocity of the cart ?
4.
• Answer A Blue dotted line
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Assume that a cart is on straight, level Rails. A motion detector is set up to record the motion of the cart in such a way that motion
away from the detector is chosen to be positive. (A) The cart remains at rest on the positive side of the motion detector for 1 second,
and then (B) starts moving away from the motion detector quickly, steadily speeding up over 2 seconds. Then (C) the cart continues
on at a constant speed for 2 seconds. Then (D) it stops abruptly, and (E) remains stopped for 1 second, before (F) moving towards
the detector, slowly, steadily speeding up over 2 seconds. Finally, (G) the cart continues on at a constant speed towards the detector
for 3 seconds. Which line in the following graph best shows the velocity of the cart ?
5.
• Answer B
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Assume that a cart is on straight, level Rails. A motion detector is set up to record the motion of the cart in such a way that motion
away from the detector is chosen to be positive. (A) The cart remains at rest on the positive side of the motion detector for 1 second,
and then (B) starts moving away from the motion detector quickly, steadily speeding up over 2 seconds. Then (C) the cart continues
on at a constant speed for 2 seconds. Then (D) it stops abruptly, and (E) remains stopped for 1 second, before (F) moving towards
the detector, slowly, steadily speeding up over 2 seconds. Finally, (G) the cart continues on at a constant speed towards the detector
for 3 seconds. Which line in the following graph best shows the velocity of the cart ?
6.
• Answer E black dotted line
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A ball rolls across a level table as shown
below.
a. What kind of motion does it have ?
b. Give three was learned in class you
could find its speed.
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• A ball rolls down a ramp as shown
• A. What kind of motion does the ball have ?
• B. Give three ways learned in class that it’s
acceleration could be determined.
• C. How can it’s acceleration be determined by
using the angle of the incline.
300
13.
13 Ball A is dropped from the top of a cliff
and Ball B is thrown out horizontally. Which
will have the greatest velocity when hitting
the ground ?
13
• Ball B will have the greatest velocity
Both have the same vertical velocity
But be has both vertical and horizontal
v
V
14.
• What would be the initial velocities in the
following situations ? ( up/right are “+”)
Vx =
Ball is dropped
Vx =
vy =
Ball is thrown horizontally with
A velocity of 10 m/s
Vx =
vy =
vy =
Ball is thrown down with
A velocity of 10 m/s
Ball is thrown up at an
angle of 200 with
a velocity of 10 m/s
Vx =
Vx =
vy =
vy =
Ball is thrown up with
A velocity of 10 m/s
Ball is thrown down at
an angle of 200 with
a velocity of 10 m/s
Vx =
vy =
•
•
•
A golf ball leaves the club at 40.0 m/s at
an angle of 55.0 degrees above the
horizontal. What is:
The range of the ball ? _____________
The maximum height achieved by the
ball ? ________________
• Range 153.5 m
• Height 54.79 m
• A tennis ball is hit at an angle of 56.8 degrees with the
horizontal at a speed of at 30.0 m/s, accidentally lands
on the roof of a building 23.7 m away.
• With what velocity will the ball land on the roof which is
30.0 m high ? _________________
• How far from the edge does it land on the roof ?
_______________
• If the initial velocity of a projectile were doubled, how
would its maximum range be affected ?
• Velocity 17.66 m/s @ 338.4 degrees
• 29.2 m
•
•
•
•
•
•
Support your answer
A = 23.4 m/s @ 220. degrees
B = 45.6 m/s @ 340. degrees
C = 22.8 m/s @ 125 degrees
Find the resultant of :
-A +B - C _________
-A +B - C
Vector
x
y
23.4 m/s @ 220.
23.4 m/s @ 40
23.4 cos 40
17.9
23.4 sin 40
15.04
45.6 m/s @ 340.
45.6 cos 340
42.85
45.6 sin 340
-15.6
22.8 m/s @ 125
22.8 m/s @ 305
22.8 cos 305
13.08
22.8 sin 305
-18.68
73.86
= sqrt 73.86² + -19,24²
-19.24
= 76.32 m/s @ 345.4
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1. What is the acceleration due to gravity for a
satellite two Earth radii above the Earth’s
surface ?
•
2. A 2.0 N object on the surface of the Earth is transported
to a planet with twice the radius and four times the
mass. How much would the object weigh on this
planet ?
9
Determine the angle at which a
frictionless curve should be banked
for a speed of 35 m/s and a turning
radius of 550m.
mv
N sin  
r
2
2
mg
v
sin   m
cos 
r
N cos   mg  0
2
v
0
  tan
 12
Rg
1
Use the diagram below of the moon,
Earth and Sun, when a lunar eclipse
occurs (the scale is obviously not
accurate)
.
What is the Net gravitation force
experienced by the moon ?
FG= ______
6.35e20 N
Find the net force on the 2.5 kg
mass relative to a line passing
horizontally through the mass
1.4
kg
2kg
.2m
1kg
2.5
kg
• 1.2e-8N @ 121.04 degrees
• How much would a 440 N person on
Earth weigh on Pluto ?
10
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A 755 N diver drops from a board 10.0 m above
the water surface. Find the speed of the diver 5.00
m above the water surface.
• Find the speed of the diver 5.00 m
above the water surface.
• Find the speed of the diver just above
the water surface.
• V @ 5.0 m = 9.90 m/s
• V just before hitting the water = 14.0 m/s
A sled and its rider together weigh 800 N. They
move down a frictionless hill through a vertical
distance of 10.0 m. What is the speed of the rider
at the bottom of the hill assuming he pushed off
with an initial speed of 5.00m/s ?
• V @ the bottom is 14.9 m/s
A pendulum consists of a ball of mass m suspended at the
end of a massless cord of length L as shown. The
pendulum is drawn aside through an angle of 600 with the
vertical and released. At the low point of its swing, the
speed of the pendulum ball is
60
L
a.
gL
b. 2gL c. 1 gL
2
d.
gL
e. 2gL
• Answer is A
• Gravity is a Conservative force
1
1
2
mgh f  mv f  mgh0  mv0 2
2
2
• Divide by m
1 2
1 2
gh f  v f  gh0  v0
2
2
• Multiply through by 2, solve for v
v  gL
A 70 kg daredevil, attached by his ankles to a
bungee cord with an unstretched length of 15 m,
drops from the top of a 50 m high bridge. The cord
stops him at water level. Assuming he is 2.0 m
tall, find the spring constant, k, of the bungee cord.
63 N/m
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Answer is C
area under the graph is distance traveled
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a. No, they are opposites
b. No, changing all the time
c. No, when U is min
d. Yes, when one max other is min
e. No, K is min
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Answer C
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Answer C
m
 f  mg sin 30  (2kg )(2 2 )
s
m
m
f  (2kg )(9.8 2 ) sin 30  (2kg )(2 2 )
s
s
f  5.8 N
34
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Answer is E
F  (3kg )a
F
a
3kg
F
FT  (1kg )(
)
3kg
F
FT 
3
35
An asteroid moves in an elliptic orbit with the Sun at one focus as shown above. Which of the following quantities increases as the
asteroid moves from point P in its orbit to point Q ?
(A) Speed
(B) Angular momentum
(C) Total energy
(D) Kinetic energy
(E) Potential energy
35
Answer E
36
The displacement x of an object moving along the x-axis is shown above as a function
of time t. The acceleration of this object must be
(A) zero
(B) constant but not zero
(D) decreasing
(C) increasing
(E) equal to g
36
Answer is A
• Slope of a x vs t is speed
• Speed is constant
• Acceleration must be = 0
37
A ball falls straight down through the air under the influence of gravity. There is a
retarding force F on the ball with magnitude given by F = bv, where v is the
speed of the ball and b is a positive constant. The magnitude of the acceleration
a of the ball at any time is equal to which of the following?
(A) g - b
(B) g - bv/m
(D) g/b
(C) g + bv/m
(E) bv/m
37
Answer B
F  ma
bv
mg
mg  bv  ma
mg  bv
a
m
bv
g
a
m
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An ideal spring obeys Hooke's law, F = -kx. A mass of 0.50 kilogram hung vertically
from this spring stretches the spring 0.075 meter. The value of the force constant for
the spring is most nearly
(A) 0.33 N/m
(B) 0.66 N/m
(D) 33 N/m
(C) 6.6 N/m
(E) 66 N/m
38
Answer E
F  ma
Fs  mg  0
Fs  mg
Fs  kx
mg
kx  mg
m
(.5kg )(9.8 2 )
mg
N
s
k

 65.33
x
.075m
m
39
Units of power include which of the following?
I. Watt
II. Joule per second
III. Kilowatt-hour
a. I only
b. III only
d. II and III only
c. I and II only
e. I, II, and III
39
Answer C
• I Yes, power is measured in Watts
• II Yes,
W so
J
P
t

s
• III No, this is energy consumption
J
1kWh  1000( )(3600s )  3.6 x106 J
s
40
Find the tension in the string
a. 19. 6 N
b. 58.8 N
c. 73.2 N
d. 7.5 N
e. 60.2 N
3 kg
6 kg
40
Both
(6kg )(9.8m / s 2 )  (9kg )( a)
m
a  6.53 2
s
Isolate
m
FT  (3kg )(6.53 2 )  19.6 N
s
m
 FT  (6kg )(9.8m / s )  (6kg )(6.53 2 )
s
m
2
FT  (6kg )(9.8m / s )  (6kg )(6.53 2 )  19.6 N
s
2
A railroad flatcar of mass 2,000 kilograms rolls to the right at 10 meters per
second and collides with a flatcar of mass 3,000 kilograms that is rolling to the left at 5
meters per second. The flatcars couple together. Their speed after the collision is
(A) I m/s
(B) 2.5 m/ s
(C) 5 m/ s
(D) 7 m/ s
(E) 7.5 m/ s
Answer is A 1 m/s
Which of the following quantities is a scalar that is always positive or zero?
(A) Power
(B) Work
(C) Kinetic energy
(E) Force
(D) Linear momentum
Answer C Kinetic Energy
• You are lowered, by helicopter, to the
middle of a frozen, frictionless pond. How
do you get to the edge ?
• Determine the type of collision and then write a
momentum equation for the following situations
• Basketball and Tennis Ball
– Elastic
(mT  mBB )v  mT vT  mBB vT
• Two carts push apart
• Elastic
0  m1v1  m2v2
• Explosion
• Elastic