Question 1

Why so much emphasis upon units? Why are units considered to be as important as the quantity, "magnitude", of something?

Accepted Answer

Just knowing the magnitude of something is not complete information (in fact it is ambiguous) unless one also knows the units. For example, learning that you will earn 150 for a certain task might mean 150 dollars, or perhaps 150 cents, or 150 pesos. The magnitude is almost worthless without the unit in which it is expressed.

Question 2

Zeros at the beginning of a number are significant.

Accepted Answer

A) True 
 B)False  False

Question 3

Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object slowing down and turning to its right?

Accepted Answer

A)   
B)   
C)   
D)   
E)    B

Question 4

A hiker walks 6.7 miles to the east in 5.1 hours, then turns around and walks 1.1 miles to the west in 1.0 hours. What was her average velocity during the trip?

Accepted Answer

A)   0.92 mph
B)   1.3 mph
C)   1.2 mph
D)   3.9 mph

Question 5

A sports car has an average acceleration of 13.1 $ \frac{\text { miles }}{\text { hour } \cdot \text { sec }} $ . How long does it take for the car to reach 60.0 mi/h, if it starts from rest?

Accepted Answer

A)   4.6 s
B)   5.5 s
C)   3.1 s
D)   8.8 s

Question 6

A 2-L bottle of soda gives you more for your money than a 2-qt bottle would, at the same price.

Accepted Answer

A) True 
 B)False

Question 7

The components of vectors $ \overrightarrow{\mathbf{B}} $and $ \overrightarrow{\mathrm{C}} $ are given as follows:
Bx = -9.2 Cx = -4.5
By = -6.1 Cy = + 4.3
The angle (less than 180 degrees) between vectors $ \overrightarrow{\mathbf{B}} $ and  $ \overrightarrow{\mathrm{C}} $ , in degrees, is closest to:

Accepted Answer

A)   77
B)   103
C)   10
D)   170
E)   84

Question 8

What is $ \frac{0.674}{0.74} $to the proper number of significant figures?

Accepted Answer

A)   0.91
B)   0.911
C)   0.9108
D)   0.9

Question 9

The equation sf = si + vis ?t + $ \frac{1}{2} $(?t)2  is valid for all types of motion because it is a fundamental equation of physics.

Accepted Answer

A) True 
 B)False

Question 10

The sum of the two vectors A and B is equal to zero. What can you conclude about A and B?

Accepted Answer

The answer of The sum of the two vectors A...

Question 11

Express 0.0015671 kg to three significant figures.

Accepted Answer

The answer of Express 0.0015671 kg to three significant figures....

Question 12

Which of the following ideas is true about projectile motion with no air drag?

Accepted Answer

A)    vx2 \mathrm{v}_{\mathrm{x}}^{2} vx2​ +  vy2 \mathrm{v}_{\mathrm{y}}^{2} vy2​ = constant.
B)   The acceleration is +g when the object is rising and -g when falling.
C)   The velocity of the object is zero at the point of maximum elevation.
D)   The trajectory will depend on the object's mass as well as its initial velocity and launch angle.
E)   The horizontal motion is independent of the vertical motion.

Question 13

Vector A points to the north and has length A. Vector B points to the east and has length B = 2.0 A. Find the magnitude of C= 4 A + B in terms of A.

Accepted Answer

A)   4.5A
B)   6A
C)   3.6A
D)   3.1A

Exam 1: Measurements in Physics, Motion in One Dimension and Motion in Two Dimensions

Why so much emphasis upon units? Why are units considered to be as important as the quantity, "magnitude", of something?

Zeros at the beginning of a number are significant.

Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object slowing down and turning to its right?

A hiker walks 6.7 miles to the east in 5.1 hours, then turns around and walks 1.1 miles to the west in 1.0 hours. What was her average velocity during the trip?

A sports car has an average acceleration of 13.1 $\frac{\text { miles }}{\text { hour } \cdot \text { sec }}$ . How long does it take for the car to reach 60.0 mi/h, if it starts from rest?

A 2-L bottle of soda gives you more for your money than a 2-qt bottle would, at the same price.

The components of vectors $\overrightarrow{\mathbf{B}}$ and $\overrightarrow{\mathrm{C}}$ are given as follows: B_x = -9.2 C_x = -4.5 B_y = -6.1 C_y = + 4.3 The angle (less than 180 degrees) between vectors $\overrightarrow{\mathbf{B}}$ and $\overrightarrow{\mathrm{C}}$ , in degrees, is closest to:

What is $\frac{0.674}{0.74}$ to the proper number of significant figures?

The equation s_f = s_i + v_is?t + $\frac{1}{2}$ (?t)² is valid for all types of motion because it is a fundamental equation of physics.

The sum of the two vectors A and B is equal to zero. What can you conclude about A and B?

Express 0.0015671 kg to three significant figures.

Which of the following ideas is true about projectile motion with no air drag?

Vector A points to the north and has length A. Vector B points to the east and has length B = 2.0 A. Find the magnitude of C= 4 A + B in terms of A.

Exam 1: Measurements in Physics, Motion in One Dimension and Motion in Two Dimensions

Why so much emphasis upon units? Why are units considered to be as important as the quantity, "magnitude", of something?

Zeros at the beginning of a number are significant.

Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object slowing down and turning to its right?

A hiker walks 6.7 miles to the east in 5.1 hours, then turns around and walks 1.1 miles to the west in 1.0 hours. What was her average velocity during the trip?

A sports car has an average acceleration of 13.1 miles hour ⋅ sec \frac{\text { miles }}{\text { hour } \cdot \text { sec }} hour ⋅ sec miles ​ . How long does it take for the car to reach 60.0 mi/h, if it starts from rest?

A 2-L bottle of soda gives you more for your money than a 2-qt bottle would, at the same price.

What is 0.6740.74 \frac{0.674}{0.74} 0.740.674​ to the proper number of significant figures?

The equation sf = si + vis ?t + 12 \frac{1}{2} 21​ (?t)2 is valid for all types of motion because it is a fundamental equation of physics.

The sum of the two vectors A and B is equal to zero. What can you conclude about A and B?

Express 0.0015671 kg to three significant figures.

Which of the following ideas is true about projectile motion with no air drag?

Vector A points to the north and has length A. Vector B points to the east and has length B = 2.0 A. Find the magnitude of C= 4 A + B in terms of A.

A sports car has an average acceleration of 13.1 $\frac{\text { miles }}{\text { hour } \cdot \text { sec }}$ . How long does it take for the car to reach 60.0 mi/h, if it starts from rest?

What is $\frac{0.674}{0.74}$ to the proper number of significant figures?

The equation s_f = s_i + v_is?t + $\frac{1}{2}$ (?t)² is valid for all types of motion because it is a fundamental equation of physics.