Answer : The net force on the object is zero. The net force on the ...

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Quiz Feedback | Introductory Physics I with Laboratory

Feedback — Newton's 2nd Law (1D): General You submitted this quiz on Thu 6 Jun 2013 6:50 PM PDT (UTC -0700). You got a score of 19.27 out of 21.00. You can attempt again, if you'd like.

Some questions provided by Matter and Interactions (3rd. Ed.), R. Chabay & B. Sherwood. Copyright (2010, John Wiley & Sons). This material is used by permission of John Wiley & Sons, Inc.

Question 1 An object is moving in the +x direction. Which, if any, of the following statements might be true? Check all that apply. Your Answer

Score

The net force on the object is in the -x direction.



0.00

The net force on the object is zero.



0.33

The net force on the object is in the +x direction.



0.33

Total

Explanation

0.67 / 1.00

Question Explanation

Answer : The net force on the object is zero. The net force on the object is in the -x direction. The net force on the object is in the +x direction. https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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Question 2 An object is moving in the +x direction. Which, if any, of the following statements do you know must be false? Check all that apply. Your Answer

Score

The net force on the object is zero.



0.25

The net force on the object is in the +x direction.



0.25

The net force on the object is in the -x direction.



0.00



0.25

vx

is zero.

Total

Explanation

0.75 / 1.00

Question Explanation

Answer : vx is zero.

Question 3 You observe three carts moving to the right. Cart A moves to the right at nearly constant speed. Cart B moves to the right, gradually speeding up. Cart C moves to the right, gradually slowing down. Which cart or carts, if any, experience a net force to the right?

Your Answer

Score

Cart B



0.33

Cart A



0.33

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Explanation

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Cart C



Total

0.33 1.00 / 1.00

Question Explanation

Answer : Cart B.

Question 4

The diagram shows the velocity of an object and the net force acting on it at some instant in time.

After a short amount of time, which of the following statements is true about the magnitude of the velocity? Your Answer

Score

Explanation

The magnitude of the velocity will decrease. The magnitude of the velocity will increase.



1.00

The magnitude of the velocity will stay the same. Total

1.00 / 1.00

Question Explanation

Answer : The magnitude of the velocity will increase. https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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Question 5

The diagram shows the velocity of an object and the net force acting on it at some instant in time.

After a short amount of time, which of the following statements is true about the direction of the velocity? Your Answer

Score

Explanation

The velocity will be in a different direction that is not parallel to the original direction. The velocity will be in the opposite direction. The direction of the velocity will be the same. Total



1.00 1.00 / 1.00

Question Explanation

Answer : The direction of the velocity will be the same.

Question 6 https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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The diagram shows the velocity of an object and the net force acting on it at some instant in time.

After a short amount of time, which of the following statements is true about the magnitude of the velocity? (You may assume that if there is any change in velocity in this situation, the time interval is short enough such that the magnitude of that change in velocity is small compared to the original velocity.) Your Answer

Score

Explanation

The magnitude of the velocity will stay increase. The magnitude of the velocity will stay the same. The magnitude of the velocity will decrease. Total



1.00 1.00 / 1.00

Question Explanation

Answer : The magnitude of the velocity will decrease.

Question 7

The diagram shows the velocity of an object and the net force acting on it at some instant in https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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time.

After a short amount of time, which of the following statements is true about the direction of the velocity? (You may assume that if there is any change in velocity in this situation, the time interval is short enough such that the magnitude of that change in velocity is small compared to the original velocity.) Your Answer

Score

Explanation

The velocity will be in a different direction that is not parallel to the original direction. The velocity will be in the opposite direction. The direction of the velocity will be the same. Total



1.00 1.00 / 1.00

Question Explanation

Answer : The direction of the velocity will be the same.

Question 8 A truck driver slams on the brakes and the velocity of the truck changes from ‹11, 0, 0 › m/s to ‹ 8, 0, 0 › m/s in 6 seconds. The truck has a mass of 12000 kg. Compute the (average) net force exerted on the truck by the surroundings. What is the x component of the net force (in Newtons)? You entered: -6000

Your Answer https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

Score

Explanation 6/16

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-6000



Total

1.00 1.00 / 1.00

Question Explanation

Answer : -6000

Question 9 Following the previous question, what is the y component of the average net force (in Newtons) exerted on the truck by the surroundings? You entered: 0

Your Answer 0

Score 

Total

Explanation

1.00 1.00 / 1.00

Question Explanation

Answer : 0

Question 10 Following the previous question, what is the z component of the average net force (in Newtons) exerted on the truck by the surroundings? You entered: 0 https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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Your Answer 0

Score 

Total

Explanation

1.00 1.00 / 1.00

Question Explanation

Answer : 0

Question 11 During a time interval of one second, a ball moves in the +x or -x direction (that is, to the right or the left), and a net force acts on the ball in the +x or -x direction. For each motion listed below, check all the descriptions of net force that could produce that behavior. More than one description may be valid for a particular motion.

(a) ball permanently at rest Your Answer

Score

net force to the left with increasing magnitude



0.14

net force to the left with constant magnitude



0.14

net force = 0



0.14

net force to the right with decreasing magnitude



0.14

net force to the right with constant magnitude



0.14

net force to the right with increasing magnitude



0.14

net force to the left with decreasing magnitude



0.14

Total

Explanation

1.00 / 1.00

Question Explanation https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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Answer : net force = 0

Question 12 (b) ball moving to the right at constant speed Your Answer

Score

net force to the right with decreasing magnitude



0.14

net force = 0



0.14

net force to the right with constant magnitude



0.14

net force to the right with increasing magnitude



0.14

net force to the left with increasing magnitude



0.14

net force to the left with decreasing magnitude



0.14

net force to the left with constant magnitude



0.14

Total

Explanation

1.00 / 1.00

Question Explanation

Answer : net force = 0

Question 13 (c) ball moving to the left at constant speed Your Answer net force = 0

https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

Score 

Explanation

0.14

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net force to the right with increasing magnitude



0.14

net force to the right with decreasing magnitude



0.14

net force to the left with increasing magnitude



0.14

net force to the left with constant magnitude



0.14

net force to the right with constant magnitude



0.14

net force to the left with decreasing magnitude



0.14

Total

1.00 / 1.00

Question Explanation

Answer : net force = 0

Question 14 (d) ball moving to the right with increasing speed Your Answer

Score

net force to the right with increasing magnitude



0.00

net force to the left with increasing magnitude



0.14

net force to the right with constant magnitude



0.14

net force to the right with decreasing magnitude



0.00

net force to the left with decreasing magnitude



0.14

net force = 0



0.14

net force to the left with constant magnitude



0.14

Total

Explanation

0.71 / 1.00

Question Explanation

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Answer : net force to the right with decreasing magnitude net force to the right with constant magnitude net force to the right with increasing magnitude

Question 15 (e) ball moving to the right with decreasing speed Your Answer

Score

net force = 0



0.14

net force to the left with decreasing magnitude



0.00

net force to the right with increasing magnitude



0.14

net force to the right with decreasing magnitude



0.14

net force to the left with increasing magnitude



0.00

net force to the right with constant magnitude



0.14

net force to the left with constant magnitude



0.14

Total

Explanation

0.71 / 1.00

Question Explanation

Answer : net force to the left with increasing magnitude https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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net force to the left with constant magnitude net force to the left with decreasing magnitude

Question 16 (f) ball moving to the left with increasing speed Your Answer

Score

net force to the right with constant magnitude



0.14

net force = 0



0.14

net force to the right with increasing magnitude



0.14

net force to the right with decreasing magnitude



0.14

net force to the left with constant magnitude



0.14

net force to the left with decreasing magnitude



0.00

net force to the left with increasing magnitude



0.00

Total

Explanation

0.71 / 1.00

Question Explanation

Answer : net force to the left with constant magnitude net force to the left with increasing magnitude https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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net force to the left with decreasing magnitude

Question 17 (g) ball moving to the left with decreasing speed Your Answer

Score

net force to the right with constant magnitude



0.14

net force to the left with increasing magnitude



0.14

net force to the right with decreasing magnitude



0.00

net force = 0



0.14

net force to the left with decreasing magnitude



0.14

net force to the right with increasing magnitude



0.00

net force to the left with constant magnitude



0.14

Total

Explanation

0.71 / 1.00

Question Explanation

Answer : net force to the right with increasing magnitude net force to the right with decreasing magnitude net force to the right with constant magnitude https://class.coursera.org/phys1-001/quiz/feedback?submission_id=59087

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Question 18 At a certain time t, a proton's position is 21.6e−09, 0, 0 3 m and the its velocity is 2 3400, 0, 0 3 m/s. The proton (mass 1.7 × 10−27 kg) experiences a net force of 2 −1.2e−11, 0, 0 3 N. At a time t + 5.1e−14 s, what is the x component of the proton's approximate velocity in m/s? (You may assume that the force was approximately constant during this interval.) You entered: 3040

Your Answer 3040

Score 

Total

Explanation

1.00 1.00 / 1.00

Question Explanation

Answer : [2986,3094]

Question 19 Following the previous question, what is the y component of the proton's approximate velocity (in m/s) at time t + 5.1e−14 s? You entered: 0

Your Answer 0

Score 

Total

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Explanation

1.00 1.00 / 1.00

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Question Explanation

Answer : 0

Question 20 Following the previous question, what is the z component of the proton's approximate velocity (in m/s) at time t + 5.1e−14 s? You entered: 0

Your Answer

0

Score



Total

Explanation

1.00 1.00 / 1.00

Question Explanation

Answer : 0

Question 21 At a certain instant a particle (mass=0.5 kg) is moving in the +x direction with velocity 14 m/s. During the next 0.14 seconds a constant force acts on the particle, with

Fx

= −8 N and

Fy

=5

N. What is the magnitude of the velocity of the particle (in m/s) at the end of this 0.14 second interval? You entered: 11.84

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Your Answer 11.84

Score 

Total

Explanation

1.00 1.00 / 1.00

Question Explanation

Answer : [11.25,12.43]

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