exam 1, 2 Flashcards
a free body diagram displays
a. the weight distribution of a body on a surface
b. the pressure distribution of a body on a surface
c. the mass distribution of a body
d. the forces acting on a body
e. none of the above
d
If two forces lying in the same plane are added together and the result is zero, which of the following is true of the forces?
a. They are opposite in direction.
b. They are equal in magnitude.
c. Both a and b are true.
d. none of the above
c
The force that acts parallel to an object in contact with a surface is called
a. friction force
b. normal contact force
c. internal force
d. colinear force
e. resolved force
a
A force can be
a. a push
b. a pull
c. either a or b
d. simultaneously a push and a pull
e. none of the above
c
A 90 kg weightlifter exerts a 1000 N force upward against a 50 kg barbell. How large is the net vertical force acting on the barbell?
a. 1050 N
b. 510 N
c. 1050 kg
d. 950 kg
e. 1490 N
b
Two teams are competing in a tug-of-war. George (170 lb), Laura (120 lb), and Jenna (110 lb) are on team A. The coefficient of static friction between their shoes and the floor is 0.40. Bill (230 lb), Hilary (140 lb), and Chelsea (130 lb) are on team B. The coefficient of static friction between their shoes and the floor is 0.30. Which team will be able to create more static friction force and thus be more likely to win the tug-of-war?
George’s team, static coefficient is greater, harder for them to move
to fully define a vector quantity, you must specify
a. length and magnitude
b. length and area
c. area and direction
d. direction and magnitude
e. none of the above
d
which of the following statements is true of the amount of horizontal force required to start in motion an object sitting on a horizontal surface
a. it must be greater than the coefficient of kinetic friction
b. it must be greater than the coefficient of static friction
c. it must be greater than the max kinetic friction force
d. it must be greater than the max static friction force
e. none of the above
d
which of the following, when present, is NOT an external force applied to a runner
a. gravitational force
b. weight
c. friction
d. muscle force
e. all of the above
c
Used to describe a force that __________ movement, traction is sometimes used in place of the term __________.
a. initiates; contact force
b. initiates; friction
c. initiates; muscle force
d. hinders; friction
e. hinders; contact force
b
Velocity is calculated as
a. distance divided by time
b. displacement divided by time
c. force divided by time
d. force times distance
e. force divided by distance
b
If an object’s initial coordinates are (3, 5, 0), and the final coordinates are (6, -2, -4), what is the object’s displacement?
a. 3 units right, 3 units down, and 4 units forward
b. 3 units left, 7 units up, and 4 units forward
c. 9 units right, 7 units down, and 4 units backward
d. 3 units right, 7 units down, and 4 units backward
e. need more information to calculate
d
At 3 s into a run, a football player is traveling at +3 m/s. Four seconds later, the player is traveling at -5 m/s. vi is equal to
a. 0 m/s
b. 3 m/s
c. 5 m/s
d. -3 m/s
e. -5 m/s
b
Units of acceleration are
a. s
b. m
c. m/s
d. m/s2
e. mi/h
d
Which of the following terms best describes linear motion along a curved line?
a. rectilinear
b. curvilinear
c. rotational
d. general
e. none of the above
b
When a runner has completed one full lap around a 400 m track, what is the runner’s displacement with respect to the starting position?
a. 400 m
b. 400 m multiplied by 2
c. zero
d. need more information to calculate
c
Which of the following is not a vector quantity?
a. distance
b. speed
c. neither a nor b
d. both a and b
d
What is the average speed of a cyclist who covers -15 mi in 30 min?
a. 5 mi/h
b. 10 mi/h
c. 30 mi/h
d. 60 mi/h
e. need more information to calculate
c
A swimmer is traveling with an average velocity of -3.2 m/s. How far does the swimmer travel in 3 s?
a. 1.1 m
b. 6.9 m
c. 9.6 m
d. A swimmer cannot travel in the negative direction.
e. need more information to calculate.
c
The horizontal velocity of Serena’s tennis serve is measured as 112 mi/h (50 m/s). Horizontally, the ball travels 82 ft (25 m) before reaching Venus (Serena’s opponent). If the ball didn’t slow down when it bounced or because of air resistance, how long would it take to reach Venus?
a. 0.25 s
b. 0.75 s
c. 0.50 s
d. 1.0 s
e. 2.0 s
c
Newton’s first law focuses on
a. action-reaction
b. acceleration
c. inertia
d. gravity
e. none of the above
c
Which of Newton’s laws is described by the equation F = ma?
a. first
b. second
c. third
d. fourth
e. law of gravitation
b
as the mass of an object increases, what happens to its inertia?
a. decrease
b. increase
c. stays the same
d. weighs more
e. mass and inertia are not related
b
if a body of constant mass is traveling with a constant velocity,
a. there must be no force acting on the body
b. there must be no net force acting on the body
c. there must be a force acting on the body
d. there must be a net force acting on the body
e. need more info
b