PHY 250 General Physics I All Graded Exams 2023/2024 100%Verified and Updated by Expert .
Question 1
Correct
6.00 points out of
6.00
What is the
... [Show More] acceleration of a skydiver at terminal velocity whose mass is 80 kg and cross-sectional area is 14 m2
. The density of the air he is falling through is 0.9984 g /
m
3
. The drag coe_cient has a value of 0.485.
Select one:
a. 15.2 m / sec2
b. 56.4 m / sec2
c. 0 m / sec2
d. 481 m / sec2
e. None of the above
Question 2
Incorrect
0.00 points out of
6.00
Calculate x = vt + 1 at2 , where v = 0.227 m/s, t = 11.1s, and a = 9.80 m/s
2
. 2
Select one:
a. 606.2487 m
b. 606 m
c. 605.5 m
d. 606.249 m
Question 3
Correct
6.00 points out of
6.00
Which of the following statements concerning an object in free fall through the atmosphere is incorrect?
Select one:
a. Air resistance opposes the motion of an object moving through air and exists because a moving object collides with air molecules.
b. The speed of a falling object increases due to the frictional force of air drag.
c. Given two spherical objects made of the same material and dropped from the same height, the one with the larger cross-sectional area will experience
increased air resistance.
d. When the magnitude of the air drag equals that of the object's weight, the net force on the object is zero. The object then falls with a maximum
constant velocity called the terminal velocity.
PHY250_TW | Chapter 3: Dynamics
The correct answer is: 0 m /sec2
The correct answer is: 606 m
The correct answer is: The speed of a falling object increases due to the frictional force of air drag.
Question 5
Correct
6.00 points out of
6.00
Which of the following is a correct statement concerning the velocity of a particle in uniform circular motion?
Select one:
a. The velocity is in the same direction as the angular velocity.
b. The velocity is directed radially inward.
c. The velocity is in the same direction as the centripetal acceleration.
d. The velocity is constantly changing directions.
Question 6
Incorrect
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Why is A · B = AxBx + AyBy
Select one:
a. It isn’t.
b. All the cross-terms are equal to zero.
c. The vectors are 90° apart.
d. The vectors are pointing in the same direction.
Question 7
Correct
6.00 points out of
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An airplane travels 600 m down a runway for take off. It starts from rest and moves with constant acceleration. It is in the air in 23 s. What is its speed when it takes
off?
Select one:
a. 7.2 m / s
b. 2.3 m / s
c. 52 m / s
d. There is not enough information provided to answer the question.
The correct answer is: Displacement: 9 blocks
Distance: 15.5 blocks
The correct answer is: The velocity is constantly changing directions.
The correct answer is: All the cross-terms are equal to zero.
The correct answer is: 52 m /s
A woman drives 2 blocks north, stops, continues on for another 4.5 blocks, and then makes a U-turn and drives south 3.25 blocks. After stopping momentarily she
drives 5.75 blocks north. Which of the following is the magnitude of the woman’s displacement and distance traveled?
Select one:
a. Displacement: 15.5 blocks
Distance: 15.5 blocks
b. Displacement: 15.5 blocks
Distance: 9 blocks
c. Displacement: 9 blocks
Distance: 15.5 blocks
d. Displacement: 9 blocks
Distance: 9 blocks
Question 4
Correct
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Question 9
Correct
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What is the scalar product of two perpendicular vectors?
Select one:
a. the total of their magnitudes
b. the product of their magnitudes
c. zero
d. the difference of their magnitudes
Question 10
Correct
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An airplane has an initial velocity with respect to the ground of 200 mph in an eastward direction. A strong wind begins to blow with a velocity of 80 mph from north tosouth. What are the x-and y-components of the total velocity of the plane when the wind is taken into account? Let north be the positive y-direction and east be the
positive x-direction.
Select one:
a. vx = +200 mph
vy = +80 mph
b. vx = +200 mph
vy = −80 mph
c. vx = +80 mph
vy = +200 mph
d. vx = +215 mph
vy = −80 mph
Question 11
Correct
6.00 points out of
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Consider a basket with 3.046 kg of fruit. When you weigh the whole package (fruit + basket), the reading on the scale is 4.2 kg. What is the most realistic weight of the basket alone?
Select one:
a. 1.2 kg
b. 1.154 kg
c. 1.15 kg
d. 1 kg
The correct answer is: −35 mph
The correct answer is: zero
The correct answer is: vx = +200 mph
vy = −80 mph
The correct answer is: 1.2 kg
Two children are playing catch in a passenger train. An observer on the ground measures that the train is traveling at 70 mph. As the train passes the observer, he
measures that the ball is thrown with half of the speed as the passenger train. What velocity do the children measure for the ball? (Assume the positive direction is
the direction in which the train is moving.)
Select one:
a. −105 mph
b. −70 mph
c. −35 mph
d. 105 mph
Question 8
Correct
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Question 13
Correct
6.00 points out of
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Which is the definition of a derived unit?
Select one:
a. A unit which can be measured directly.
b. A unit which can not be measured directly.
c. A unit which is based on other (basic) units.
d. A unit which can be derived from a mathematical formula.
Question 14
Correct
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A small mass is placed on a turntable that is rotating at 45 rpm. The centripetal acceleration is .
Select one:
a. greater when the mass is closer to the center of the circle
b. greater when the mass is farther from the center of the circle
c. independent of the location of the mass
d. zero
Question 15
Correct
6.00 points out of
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Which of the following is not a frictional force between solids?
Select one:
a. static friction
b. kinetic friction
c. viscosity
d. rolling friction
The correct answer is: mass
The correct answer is: A unit which is based on other (basic) units. [Show Less]