StraighterLine PHY 250 General Physics Latest Exam With Verified Questions & Answers
What is the 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 fallingthrough is 0.9984 g / m3. The drag coe_cient has a value of...
StraighterLine PHY 250 General
Physics Latest Exam With
l Verified Questions &Answers
PHY250_TW | Chapter 3: Dynamics
Question 1
What is the 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 fallingthrough is 0.9984 g /
Correct m3. The drag coe_cient has a value of 0.485.
6.00 points outof
6.00 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
The correct answer is: 0 m /sec2
Question 2 1 2
Calculate x = vt + at , where v = 0.227 m/s, t = 11.1s, and a = 9.80 m/s2 .
Incorrect
2
0.00 points outof
6.00
Select one:
a. 606.2487 m
b. 606 m
c. 605.5 m
d. 606.249 m
The correct answer is: 606 m
Question 3
Which of the following statements concerning an object in free fall through the atmosphere is incorrect?
Correct
6.00 points outof Select one:
6.00 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 willexperience
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 amaximum
constant velocity called the terminal velocity.
The correct answer is: The speed of a falling object increases due to the frictional force of air drag.
, StraighterLine PHY 250 General
Physics Latest Exam With
l Verified Questions &Answers
Question 4 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 stoppingmomentarily she
Correct drives 5.75 blocks north. Which of the following is the magnitude of the woman’s displacement and distance traveled?
6.00 points outof
6.00 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
The correct answer is: Displacement: 9 blocks
Distance: 15.5 blocks
Question 5
Which of the following is a correct statement concerning the velocity of a particle in uniform circular motion?
Correct
6.00 points outof Select one:
6.00 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.
The correct answer is: The velocity is constantly changing directions.
Question 6
Why is A · B = AxBx + AyBy
Incorrect
0.00 points outof
6.00
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.
The correct answer is: All the cross-terms are equal to zero.
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 itsspeed when it takes
off?
Select one:
Question 7 a. 7.2 m /s
Correct b. 2.3 m /s
6.00 points outof c. 52 m / s
6.00
d. There is not enough information provided to answer the question.
, StraighterLine PHY 250 General
Physics Latest Exam With
l Verified Questions &Answers
The correct answer is: 52 m /s
, Question 8 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
Correct 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
6.00 points outof
the direction in which the train is moving.)
6.00
Select one:
a. −105 mph
b. −70 mph
c. −35 mph
d. 105 mph
The correct answer is: −35 mph
Question 9
What is the scalar product of two perpendicular vectors?
Correct
6.00 points outof Select one:
6.00 a. the total of their magnitudes
b. the product of their magnitudes
c. zero
d. the difference of their magnitudes
The correct answer is: zero
Question 10 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 80mph from north to
Correct south. 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
6.00 points outof
positive x-direction.
6.00
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
The correct answer is: vx = +200 mph
vy = −80 mph
Question 11
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 mostrealistic weight of the
Correct basket alone?
6.00 points outof
6.00 Select one:
a. 1.2 kg
b. 1.154 kg
c. 1.15 kg
d. 1 kg
The correct answer is: 1.2 kg
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