Question 1

The Moon is accelerated toward the earth, so it is gradually getting closer to the earth.

Accepted Answer

A)  True 
B)  False 
C)  The moon is not accelerated toward the earth. 
A)  True 
B)  False 
C)  The moon is not accelerated toward the earth.

Question 2

If vector $\vec { A }$ has components Ax = -3.0 lb and Ay = -4.0 lb, and vector $\overrightarrow { \mathbf { B } }$ has components Bx = 3.0 lb and By = -8.0 lb, what is the magnitude of vector $\overrightarrow { \mathrm { C } }$ = $\vec { A }$ - $\overrightarrow { \mathbf { B } }$ ?

Accepted Answer

A)  13 lb 
B)  16 lb 
C)  140 lb 
D)  7.2 lb 
A)  13 lb 
B)  16 lb 
C)  140 lb 
D)  7.2 lb

Question 3

If a satellite moves with constant speed in a perfectly circular orbit around the earth, what is the direction of the acceleration of the satellite?

Accepted Answer

A)  in the forward direction 
B)  in the backward direction 
C)  outward away from the earth 
D)  inward toward the earth 
E)  The acceleration is zero because the speed is constant. 
A)  in the forward direction 
B)  in the backward direction 
C)  outward away from the earth 
D)  inward toward the earth 
E)  The acceleration is zero because the speed is constant.

Question 4

An object moves with a constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the object?

Accepted Answer

A)  0 m/s2 
B)  0.17 m/s2 
C)  5.0 m/s2 
D)  6.0 m/s2 
A)  0 m/s2 
B)  0.17 m/s2 
C)  5.0 m/s2 
D)  6.0 m/s2

Question 5

Shown below are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object's velocity changing while its speed is not changing?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 6

The magnitude of a vector an only zero if all of its components are zero.

Accepted Answer

A) True 
 B)False

Question 7

An airplane undergoes the following displacements, all at the same altitude: First, it flies $59.0 \mathrm {~km}$ in a direction 30.0° east of north. Next, it flies $58.0 \mathrm {~km}$ due south. Finally, it flies $100 \mathrm {~km}$ 30.0° north of west. Use components to determine how far the airplane ends up from its starting point.

Accepted Answer

A)  71.5 km 
B)  73.0 km 
C)  74.4 km 
D)  70.1 km 
E)  68.7 km 
A)  71.5 km 
B)  73.0 km 
C)  74.4 km 
D)  70.1 km 
E)  68.7 km

Question 8

Three vectors, $\overrightarrow { \mathrm { S } }$ , $\overrightarrow { \mathrm { T } }$ , and $\overrightarrow { \mathrm { U } }$ , have the components shown in the table. What is the magnitude of the resultant of these three vectors? $\begin{array} { | c | c | c | } 
\hline & x \text { component } & y \text { component } \
\hline \overrightarrow { \mathrm { S } } & & \
& 3.50 \mathrm {~m} & - 4.50 \mathrm {~m} \
\hline \overrightarrow { \mathrm { T } } & & \
& 2.00 \mathrm {~m} & 0.00 \mathrm {~m} \
\hline \overrightarrow { \mathrm { U } } & & \
& - 5.50 \mathrm {~m} & 2.50 \mathrm {~m} \
\hline
\end{array}$

Accepted Answer

A)  5.50 m 
B)  13.0 m 
C)  11.1 m 
D)  7.00 m 
E)  2.00 m 
A)  5.50 m 
B)  13.0 m 
C)  11.1 m 
D)  7.00 m 
E)  2.00 m

Question 9

Your motorboat can move at 30 km/h in still water. What is the minimum time it will take you to move 12 km downstream in a river flowing at 6.0 km/h?

Accepted Answer

A)  20 min 
B)  22 min 
C)  24 min 
D)  30 min 
A)  20 min 
B)  22 min 
C)  24 min 
D)  30 min

Question 10

An airplane flies between two points on the ground that are 500 km apart. The destination is directly north of the point of origin of the flight. The plane flies with an airspeed of 120 m/s. If a constant wind blows at 10 m/s toward the west during the flight, what direction must the plane fly relative to the air to arrive at the destination?

Accepted Answer

A)  4.8° east of north 
B)  5.9° east of north 
C)  85° west of north 
D)  4.8° west of north 
E)  5.9° west of north 
A)  4.8° east of north 
B)  5.9° east of north 
C)  85° west of north 
D)  4.8° west of north 
E)  5.9° west of north

Question 11

A child sits on a merry-go-round, 1.5 meters from the center. The merry-go-round is turning at a constant rate, and the child is observed to have a radial acceleration of 2.3 m/s2. How long does it take for the merry-go-round to make one revolution?

Accepted Answer

Question 12

A 5.0-kg stone is thrown upward at 7.5 m/s at an angle of 51° above the horizontal from the upper edge of a cliff, and it hits the ground 1.5 s later with no air resistance. Find the magnitude of its velocity vector just as it reaches the ground.

Accepted Answer

The answer of A 5.0-kg stone is thrown upward at...

Question 13

A marble moving 1.48 m/s rolls off the top edge of a 125-cm high table in a room where there is no appreciable air resistance and the acceleration due to gravity is 9.80 m/s2.
(a) How far from the base of the table will it strike the floor?
(b) How long will it be in the air?

Accepted Answer

(a) 75.0 c

Question 14

A hockey puck slides off the edge of a horizontal platform with an initial velocity of 28.0 m/shorizontally in a city where the acceleration due to gravity is 9.81 m/s2. The puck experiences no significant air resistance as it falls. The height of the platform above the ground is 2.00 m. What is the angle below the horizontal of the velocity of the puck just before it hits the ground?

Accepted Answer

A)  77.2° 
B)  72.6° 
C)  12.8° 
D)  12.6° 
E)  31.8° 
A)  77.2° 
B)  72.6° 
C)  12.8° 
D)  12.6° 
E)  31.8°

Question 15

A ball rolls over the edge of a platform with only a horizontal velocity. The height of the platform is 1.6 m and the horizontal range of the ball from the base of the platform is 20 m. What is the horizontal velocity of the ball just before it touches the ground? Neglect air resistance.

Accepted Answer

A)  35 m/s 
B)  9.8 m/s 
C)  20 m/s 
D)  4.9 m/s 
E)  70 m/s 
A)  35 m/s 
B)  9.8 m/s 
C)  20 m/s 
D)  4.9 m/s 
E)  70 m/s

Question 16

A projectile is shot horizontally at 23.4 m/s from the roof of a building 55 m tall and experiences negligible air resistance.
(a) Determine the time necessary for the projectile to reach the ground below.
(b) Determine the distance from the base of the building that the projectile lands.
(c) Determine the horizontal and vertical components of the velocity just before the projectile reaches the ground.

Accepted Answer

(a) 3.4 s (b) 78 m (

Question 17

You walk $33 \mathrm {~m}$ to the north, then turn 60° to your right and walk another $45 \mathrm {~m} .$ How far are you from where you originally started?

Accepted Answer

A)  68 m 
B)  39 m 
C)  75 m 
D)  35 m 
A)  68 m 
B)  39 m 
C)  75 m 
D)  35 m

Question 18

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below if there is no air resistance.

Accepted Answer

A)  James reaches the surface of the lake first. 
B)  John reaches the surface of the lake first. 
C)  James and John will reach the surface of the lake at the same time. 
D)  Cannot be determined without knowing the mass of both James and John. 
E)  Cannot be determined without knowing the weight of both James and John. 
A)  James reaches the surface of the lake first. 
B)  John reaches the surface of the lake first. 
C)  James and John will reach the surface of the lake at the same time. 
D)  Cannot be determined without knowing the mass of both James and John. 
E)  Cannot be determined without knowing the weight of both James and John.

Question 19

An airplane with an airspeed of 140 km/h has a heading of 50° west of north in a wind that is blowing toward the east at 25 km/h. What is the groundspeed of the plane?

Accepted Answer

The answer of An airplane with an airspeed of 140...

Question 20

The figure shows three vectors, $\vec { A }$ , $\overrightarrow { \mathbf { B } }$ , and $\overrightarrow { \mathrm { C } }$ , having magnitudes 7.0 cm, 6.0 cm, and 4.0 cm, respectively. Find the x and y components of the resultant of these three vectors.

Accepted Answer

-11 cm (x

Exam 3: Vectors and Motion in Two Dimensions

The Moon is accelerated toward the earth, so it is gradually getting closer to the earth.

If vector A⃗\vec { A }A has components Ax = -3.0 lb and Ay = -4.0 lb, and vector B→\overrightarrow { \mathbf { B } }B has components Bx = 3.0 lb and By = -8.0 lb, what is the magnitude of vector C→\overrightarrow { \mathrm { C } }C = A⃗\vec { A }A - B→\overrightarrow { \mathbf { B } }B ?

If a satellite moves with constant speed in a perfectly circular orbit around the earth, what is the direction of the acceleration of the satellite?

An object moves with a constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the object?

Shown below are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object's velocity changing while its speed is not changing?

The magnitude of a vector an only zero if all of its components are zero.

Your motorboat can move at 30 km/h in still water. What is the minimum time it will take you to move 12 km downstream in a river flowing at 6.0 km/h?

A child sits on a merry-go-round, 1.5 meters from the center. The merry-go-round is turning at a constant rate, and the child is observed to have a radial acceleration of 2.3 m/s2. How long does it take for the merry-go-round to make one revolution?

A 5.0-kg stone is thrown upward at 7.5 m/s at an angle of 51° above the horizontal from the upper edge of a cliff, and it hits the ground 1.5 s later with no air resistance. Find the magnitude of its velocity vector just as it reaches the ground.

A marble moving 1.48 m/s rolls off the top edge of a 125-cm high table in a room where there is no appreciable air resistance and the acceleration due to gravity is 9.80 m/s2. (a) How far from the base of the table will it strike the floor? (b) How long will it be in the air?

A ball rolls over the edge of a platform with only a horizontal velocity. The height of the platform is 1.6 m and the horizontal range of the ball from the base of the platform is 20 m. What is the horizontal velocity of the ball just before it touches the ground? Neglect air resistance.

You walk 33 m33 \mathrm {~m}33 m to the north, then turn 60° to your right and walk another 45 m.45 \mathrm {~m} .45 m. How far are you from where you originally started?

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below if there is no air resistance.

An airplane with an airspeed of 140 km/h has a heading of 50° west of north in a wind that is blowing toward the east at 25 km/h. What is the groundspeed of the plane?

The figure shows three vectors, A⃗\vec { A }A , B→\overrightarrow { \mathbf { B } }B , and C→\overrightarrow { \mathrm { C } }C , having magnitudes 7.0 cm, 6.0 cm, and 4.0 cm, respectively. Find the x and y components of the resultant of these three vectors.

Representing Motion

Motion in One Dimension

Forces and Newtons Laws of Motion

Applying Newtons Laws

Gravity

Rotational Motion

Equilibrium Ad Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Current and Resistance

Circuits

Magnetic Fields and Forces

EM Induction and Em Waves

AC Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

Filters

If vector $\vec { A }$ has components A_x = -3.0 lb and A_y = -4.0 lb, and vector $\overrightarrow { \mathbf { B } }$ has components B_x = 3.0 lb and B_y = -8.0 lb, what is the magnitude of vector $\overrightarrow { \mathrm { C } }$ = $\vec { A }$ - $\overrightarrow { \mathbf { B } }$ ?

A child sits on a merry-go-round, 1.5 meters from the center. The merry-go-round is turning at a constant rate, and the child is observed to have a radial acceleration of 2.3 m/s². How long does it take for the merry-go-round to make one revolution?

A marble moving 1.48 m/s rolls off the top edge of a 125-cm high table in a room where there is no appreciable air resistance and the acceleration due to gravity is 9.80 m/s². (a) How far from the base of the table will it strike the floor? (b) How long will it be in the air?

You walk $33 \mathrm {~m}$ to the north, then turn 60° to your right and walk another $45 \mathrm {~m} .$ How far are you from where you originally started?