Physics Questions I Get Wrong
Given a graph of position vs time, how do you determine the position of an object at t = 5 s?
Read directly from the vertical axis at t = 5 s.
How is inertia best defined?
The property responsible for an object's resistance to changes in motion
Which of the following best defines what inertia is?
The property responsible for an object's resistance to changes in motion
C depends on what
shape and texture
Given a graph of velocity vs time, how do you determine the position of an object at t = 7 s?
Find the area between the graph and the horizontal axis from t = 0 to 7 s.
Under what circumstances does Newton's Second Law become Newton's First Law?
If the object is not accelerating
In vertical free fall, the speed of falling objects _______ by _________
increases, 10m/s
A person travels for a certain time with a speed of 6 m/s and then travels the same amount of time with a speed of 10 m/s. The average speed of this person over the whole time in motion:
is equal to 8 m/s
A position vs time graph shows a horizontal line below the horizontal (time) axis. This means that the object is:
not moving
For an object on a surface, there can be _____ value(s) for the kinetic frictional force and _____ value(s) for the static frictional force.
one; many
Drag force is ____
opposite of the direction the object is moving
Which of the following inequalities is true for the coefficients of friction?
1 > mu(s) > mu(k) > 0
FD =
1/2C(phi)A(v)^2
Gravity causes objects to accelerate at ________
10 m/s^2
For an object launched at a 30 degree angle above the horizontal, which of the following is true about the velocity and acceleration of the object when it reaches the highest point? Select TWO answers.
Acceleration is vertical. Velocity is horizontal.
The frictional force acting on a moving object directly depends on which two things? Select TWO answers.
Coefficient of kinetic friction Normal force acting on the object
The gravitational force acting on an object depends on which two things? Select TWO answers.
Location of the object Mass of the object
Which of the following is another name for the gravitational force acting on an object?
Weight
If the object starts and ends at the same height:
Tup = Tdown = 1/2 total
At any height
Vup = -Vdown
At all points
a = -g
A rock is thrown straight upward. Which of the following is true of the velocity and acceleration at the highest point? Select TWO answers.
a. Acceleration is directed downward. c. Velocity is zero.
If an object is in equilibrium, this means that which of the following MUST be true? Select ALL that apply.
a. The forces acting on the object are balanced. b. The object has zero acceleration. c. The net force on the object must be zero.
If an object is speeding up, the acceleration must be:
a. in the same direction as the velocity
A person stands on a scale in an elevator. In which of the following situations is the reading on the scale equal to the person's true weight? Select ALL that apply.
b. The elevator is moving upward at a constant speed c. The elevator is not moving.This answer is correct. e. The elevator is moving downward at a constant speed.
FD =
bV
Which of the following forces act on an object that is in free fall?
c. Gravitational force only
The gravitational force acting on an object is also known by what name?
c. Weight
In vertical free fall, the speed of rising objects _______ by _________
decreases, 10m/s
A is
the cross-sectional area of the object perpendicular to the direction of the object
phi is
the density of the surrounding fluid
As speed increases on an object not in free fall...
the drag force increases
When a person stands on a scale, the scale will always give a reading of:
the normal force acting on the person
At top of path:
v = 0
When an object is first launched
v0 != 0
When is terminal velocity reached?
when drag force equals gravitational force, and the object no longer accelerates