Question 1

The magnitude of the resultant of two vectors cannot be less than the magnitude of either of those
two vectors.

Accepted Answer

A) True 
 B)False

Question 2

When rolled down a mountainside at 7.0 m/s, the horizontal component of its velocity vector was 1.8 m/s. What was the angle of the mountain surface above the horizontal?

Accepted Answer

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

Question 3

A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true?

Accepted Answer

A)  During the collision, the force on the truck is smaller than the force on the car. 
B)  During the collision, the force on the truck is equal to the force on the car. 
C)  The car did not slow down during the collision, but the truck did. 
D)  During the collision, the force on the truck is greater then the force on the car. 
E)  The truck did not slow down during the collision, but the car did. 
A)  During the collision, the force on the truck is smaller than the force on the car. 
B)  During the collision, the force on the truck is equal to the force on the car. 
C)  The car did not slow down during the collision, but the truck did. 
D)  During the collision, the force on the truck is greater then the force on the car. 
E)  The truck did not slow down during the collision, but the car did.

Question 4

A child throws a ball with an initial speed of 8.0 m/s at an angle of   ° above the horizontal. The ball leaves her hand 1.0 m above the ground. At what angle below the horizontal does the ball
Approach the ground?

Accepted Answer

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

Question 5

Alicia intends to swim to a point straight across a 100 m wide river with a current that
flows at 1.2 m/s. She can swim 2.5 m/s in still water. At what angle, measured from the
upstream direction, must she swim upstream to achieve her goal?

Accepted Answer

The answer of Alicia intends to swim to a point...

Question 6

A cat leaps to try to catch a bird. If the cat's jump was at   off the ground and its initial velocity was 2.74 m/s, what is the highest point of its trajectory, neglecting air resistance?

Accepted Answer

A)  10.96 m 
B)  0.19 m 
C)  0.58 m 
D)  0.29 m 
A)  10.96 m 
B)  0.19 m 
C)  0.58 m 
D)  0.29 m

Question 7

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)    west of north 
B)    west of north 
C)    east of north 
D)    west of north 
E)    east of north 
A)    west of north 
B)    west of north 
C)    east of north 
D)    west of north 
E)    east of north

Question 8

Displacement vector   is  75cm  long and points at   above the  +x -axis. Displacement vector   is  25 cm  long and points along the  -x -axis. Displacement vector   is  40 cm long and points at   below the  -x -axis.
(a) Determine the  x  and  y  components of vector  
(b) Determine the  x  and  y  components of vector  
(c) Determine the  x  and  y  components of vector  
(d) Determine the  x  and  y  components of the resultant of these three vectors.
(e) Determine the magnitude and direction of the resultant of these three vectors.

Accepted Answer

(a) 11ec81c2_f3bb_27b1_b208_87044ec7eafe

Question 9

Enzo throws a rock horizontally with a speed of 12 m/s from a bridge. It falls for 2.28 s
before reaching the water below with no appreciable air resistance. Just as the rock
reaches the water, find
(a) the horizontal component of its velocity.
(b) the speed with which it is moving.

Accepted Answer

(a) 12 m/s

Question 10

A plane flies directly from city A to city B, which are separated by 2300 mi. From A to B, the plane flies into a 65 mi/h headwind. On the return trip from B to A, the wind velocity is unchanged. The
Trip from B to A takes 65 min less than the trip from A to B. What is the airspeed (assumed
Constant) of the plane relative to the air (that is, the airspeed)?

Accepted Answer

A)  610 mi/h 
B)  400 mi/h 
C)  480 mi/h 
D)  530 mi/h 
A)  610 mi/h 
B)  400 mi/h 
C)  480 mi/h 
D)  530 mi/h

Question 11

A vector    has components  
(a) What is the angle that vector     makes with the  
(b) What is the magnitude of vector

Accepted Answer

(a) 11ec81c0_2465_86

Question 12

An airplane with an airspeed of 140 km/h has a heading of   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 13

A boat, whose speed in still water is 1.75 m/s, must aim upstream at an angle of 26.3°
(with respect to a line perpendicular to the shore) in order to travel directly across the
stream.
(a) What is the speed of the current?
(b) What is the resultant speed of the boat with respect to the shore?

Accepted Answer

(a)  0.775

Question 14

On a calm day with no wind, you can run a 1500-m race at a velocity of 4.0 m/s. If you run the same race on a day when you have a constant headwind that slows your speed by 2.0 m/s,
Much time would it take you to finish the race?

Accepted Answer

A)  250 s 
B)  750 s 
C)  9000 s 
D)  1125 s 
A)  250 s 
B)  750 s 
C)  9000 s 
D)  1125 s

Question 15

A car travels 20 km west and then 20 km south. What is the magnitude of its displacement vector?

Accepted Answer

A)  40 km 
B)  20 km 
C)  28 km 
D)  0 km 
A)  40 km 
B)  20 km 
C)  28 km 
D)  0 km

Question 16

The figure shows three vectors and their magnitudes and relative directions. The magnitude of the resultant of the three vectors is closest to

Accepted Answer

A)  19 
B)  13 
C)  10 
D)   7.0 
E)  16 
A)  19 
B)  13 
C)  10 
D)   7.0 
E)  16

Question 17

Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are added together, the magnitude of the sum

Accepted Answer

A)  is equal to 2.0 m. 
B)  is equal to 12 m. 
C)  could be as small as 2.0 m or as large as 12 m. 
D)  is equal to 8.6 m. 
A)  is equal to 2.0 m. 
B)  is equal to 12 m. 
C)  could be as small as 2.0 m or as large as 12 m. 
D)  is equal to 8.6 m.

Question 18

Two perpendicular vectors,   , are added together giving vector   If the magnitudes of both vectors   are doubled without changing their directions, the magnitude of vector   will

Accepted Answer

A)  increase by a factor of   
B)  increase by a factor of  2 . 
C)  increase by a factor of  8 . 
D)  increase by a factor of  4 . 
E)  not change. 
A)  increase by a factor of   
B)  increase by a factor of  2 . 
C)  increase by a factor of  8 . 
D)  increase by a factor of  4 . 
E)  not change.

Question 19

If A - B = 0, then the vectors A and B have equal magnitudes and are directed in the same
direction.

Accepted Answer

A) True 
 B)False

Question 20

A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's
Motion are true just before it hits the ground? (There could be more than one correct choice.)

Accepted Answer

A)  Its horizontal velocity component is zero. 
B)  Its vertical velocity component is the same as it was just as it was launched. 
C)  Its horizontal velocity component is the same as it was just as it was launched. 
D)  Its speed is the same as it was just as it was launched. 
E)  Its velocity is vertical. 
A)  Its horizontal velocity component is zero. 
B)  Its vertical velocity component is the same as it was just as it was launched. 
C)  Its horizontal velocity component is the same as it was just as it was launched. 
D)  Its speed is the same as it was just as it was launched. 
E)  Its velocity is vertical.

Exam 3: Kinematics in Two Dimensions; Vectors

The magnitude of the resultant of two vectors cannot be less than the magnitude of either of those two vectors.

When rolled down a mountainside at 7.0 m/s, the horizontal component of its velocity vector was 1.8 m/s. What was the angle of the mountain surface above the horizontal?

A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true?

A child throws a ball with an initial speed of 8.0 m/s at an angle of ° above the horizontal. The ball leaves her hand 1.0 m above the ground. At what angle below the horizontal does the ball Approach the ground?

Alicia intends to swim to a point straight across a 100 m wide river with a current that flows at 1.2 m/s. She can swim 2.5 m/s in still water. At what angle, measured from the upstream direction, must she swim upstream to achieve her goal?

A cat leaps to try to catch a bird. If the cat's jump was at off the ground and its initial velocity was 2.74 m/s, what is the highest point of its trajectory, neglecting air resistance?

Enzo throws a rock horizontally with a speed of 12 m/s from a bridge. It falls for 2.28 s before reaching the water below with no appreciable air resistance. Just as the rock reaches the water, find (a) the horizontal component of its velocity. (b) the speed with which it is moving.

A vector has components (a) What is the angle that vector makes with the (b) What is the magnitude of vector

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

A boat, whose speed in still water is 1.75 m/s, must aim upstream at an angle of 26.3° (with respect to a line perpendicular to the shore) in order to travel directly across the stream. (a) What is the speed of the current? (b) What is the resultant speed of the boat with respect to the shore?

On a calm day with no wind, you can run a 1500-m race at a velocity of 4.0 m/s. If you run the same race on a day when you have a constant headwind that slows your speed by 2.0 m/s, Much time would it take you to finish the race?

A car travels 20 km west and then 20 km south. What is the magnitude of its displacement vector?

The figure shows three vectors and their magnitudes and relative directions. The magnitude of the resultant of the three vectors is closest to

Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are added together, the magnitude of the sum

Two perpendicular vectors, , are added together giving vector If the magnitudes of both vectors are doubled without changing their directions, the magnitude of vector will

If A - B = 0, then the vectors A and B have equal magnitudes and are directed in the same direction.

A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's Motion are true just before it hits the ground? (There could be more than one correct choice.)

Introduction, Measurement, Estimating

Describing Motion: Kinematics in One Dimension

Dynamics: Newtons Laws of Motion

Circular Motion; Gravitation

Work and Energy

Linear Momentum

Rotational Motion

Static Equilibrium; Elasticity and Fracture

Fluids

Oscillations and Waves

Sound

Temperature and Kinetic Theory

Heat

The Laws of Thermodynamics

Electric Charge and Electric Field

Electric Potential

Electric Currents

Dc Circuits

Magnetism

Electromagnetic Induction and Faradays Law

Electromagnetic Waves

Light: Geometric Optics

The Wave Nature of Light

Optical Instruments

The Special Theory of Relativity

Early Quantum Theory and Models of the Atom

Quantum Mechanics of Atoms

Molecules and Solids

Nuclear Physics and Radioactivity

Nuclear Energy; Effects and Uses of Radiation

Elementary Particles

Astrophysics and Cosmology

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