Description of Motion - Scalar vs Vector Quantities

Practice Problems
Description of Motion - Scalar vs Vector Quantities

Directions: On this worksheet you will practice with the basic definitions of introductory motion.

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Question 1 A bike messenger traveled 3 blocks North, 4 blocks East, 7 blocks South, and finally 9 blocks West in order to deliver a package in the traffic, congested city. If his trip took 42 minutes, what was the magnitude of his average velocity in blocks/minute?

2.3 x 10¹6.4 x 10⁰1.52 x 10^-12.14 x 10^-15.48 x 10^-1

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Question 2 If the messenger in Question #1 could have traveled directly to his destination, what would have been the direction of his net displacement?

218.7 deg212.0 deg148.0 deg128.7 deg141.3 deg

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Question 3 The magnitude of an object's average velocity can ONLY equal the magnitude of its average speed when the object is

standing stilltraveling in a
straight linetraveling in a circletraveling in successive
directions that change by 90º

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Question 4 A scalar is a quantity that can be completely described by stating its

directionsize and directionsize

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Question 5 A family taking a vacation traveled 4 hours at 65 mph and then 3 hours at only 48 mph. What was their average speed during this trip?

57.7 mph55.3 mph48.9 mph56.5 mph

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Question 6 Which quantity is NOT a scalar?

timemassdistanceacceleration

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Question 7 Which description of an object's motion is more specific: moving at a constant speed or moving at a constant velocity?

constant speed since it demands that the object
has to maintain a constant rate
regardless of its direction of motionconstant velocity since it demands that the object
not only move at a constant rate,
but also maintain a constant directionthe two terms are completely equivalent

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Question 8 A student warming up for practice travels one full circuit, 400 meters, around the track. Initially he jogs 84 meters at 1.5 m/sec, then runs 252 meters at 2.2 m/sec, and finally cools down by finishing the final 64 meters at 1.0 m/sec. What was his average speed?

1.57 m/sec2.35 m/sec1.86 m/sec1.71 m/sec

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Question 9 What was the student's average velocity in Question #8?

0 m/secthe same as his average speedcannot be determined

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Question 10 During a 30 minute period of time, one car moves at a constant velocity of 45 mph, N, while a second car moves at a constant velocity of 45 mph, W. During this time interval, the cars would have the same

A. instantaneous speed

B. instantaneous velocity

C. displacement

D. acceleration

B and CA and DC and DB and DA and C

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Question 11 A moving van completes its journey of 630 kilometers in 9 hours. Approximately how far should it have traveled 7 hours after beginning its trip?

381 km90 km490 km140 km