72 terms

Phyiscal Science Honors Midterm

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What kind of quantity is distance?
scalar
what kind of quantity is displacement
vector
what kind of quantity is speed
scalar
what kind of quantity is velocity
vector
What is a system of knowledge and the methods used to find that knowledge?
science
What happens when the data in an investigation do not support the original hypothesis?
The hypothesis is revised
Why are scientific models important?
They help visualize things that are very complex, very large, or very small.
Which of the following is an example of a safe laboratory procedure?
a. tying back long hair and loose clothing
b. eating or drinking from laboratory glassware
c. touching hot objects with your bare hands
d. testing an odor by directly inhaling the vapor
tying back long hair and loose clothing
How is 0.00069 written in scientific notation?
6.9 10-4
The slope of a line on a distance-time graph is
speed.
A horizontal line on a distance-time graph means the object is
at rest
Which example identifies a change in motion that produces acceleration?
a. a speed skater moving at a constant speed on a straight track
b. a ball moving at a constant speed around a circular track
c. a particle moving in a vacuum at constant velocity
d. a vehicle moving down the street at a steady speed
b
Objects in free fall near the surface of the Earth experience
constant acceleration
Which example describes constant acceleration due ONLY to a change in direction?
a. increasing speed while traveling around a curve
b. an object at rest
c. traveling around a circular track
d. an object in free fall
C
The slope of a speed-time graph indicates
acceleration
An object that is accelerating may be
a. slowing down. c. changing direction.
b. gaining speed. d. all of the above
D
What is instantaneous acceleration?
how fast a velocity is changing at a specific instant
Which of the following statements is true?
a. An object that is accelerating is always changing direction.
b. An object has an instantaneous acceleration, even if the acceleration vector is zero.
c. An object at rest has an instantaneous acceleration of zero.
d. Instantaneous acceleration is always changing.
c
When an unbalanced force acts on an object...
b
When a pair of balanced forces acts on an object, the net force that results is
equal to zero
As you push a cereal box across a tabletop, the sliding friction acting on the cereal box
acts in the direction opposite of motion.
Projectile motion is caused by
the downward force of gravity and an initial forward velocity
The property of matter that resists changes in motion
inertia
An orange might roll off your cafeteria tray when you stop suddenly because of
the orange's inertia.
What is conserved when two objects collide in a closed system?
momentum
The gravitational force between two objects increases as mass
increases or distance decreases
The force that keeps an object moving in a circle is called
centripetal force
The centripetal force acting on a satellite in orbit
acts as an unbalanced force on the satellite. changes the direction of the satellite. is a center-directed force.
The SI base unit of temperature
kelvin
A measurement must include both a number and a(an)
unit
a way of organizing data that is used to show changes that occur in related variables.
line graph
two main areas of physical science are physics and _____
chemistry
the variable that changes in response to the manipulated variable
responding variable
a statement that summarizes a pattern found in nature.
scientific law
explains a pattern found in nature
scientific theory
The valid digits in a measurement
sig. fig.
The valid digits in a measurement
sig. digits
The motion of an object looks different to observers in different _____
frames of reference
The direction and length of a straight line from the starting point to the ending point of an object's motion
displacement
Displacement and velocity are examples of ________ because they have both magnitude and direction
vectors
constant slope on a distance-time graph indicates ____
constant speed
The difference between speed and velocity is that velocity indicates the _______ of motion and speed does not
direction
A moving object does not __________ if its velocity remains constant
accelerate
Freely falling objects accelerate at 9.8 m/s2 because the force of _________ acts on them
gravity
The velocity of an object moving in a straight line changes at a constant rate when the object is experiencing constant ________
acceleration
Accelerated motion is represented by a(an) ________ line on a distance-time graph
curved
If the forces acting on an object produce a net force of zero, the forces are called ___
balanced forces
The force that opposes the motion of objects that touch as they move past each other is called _______
friction
It usually takes more force to start an object sliding than it does to keep an object sliding because static friction is usually _______ than sliding friction.
greater
what are the 2 forces acting on a falling object
gravity and air resistance
When a falling object reaches terminal velocity, the net force acting on it is ____
zero
During a head-on auto collision, _______ causes a passenger in the front seat to continue moving ________.
inertia; forward
In a closed system, the loss of momentum of one object ______ the gain in momentum of another object
equals
The universal force that is effective over the longest distances
gravity
The centripetal force acting on the moon continuously changes the _________ of the moon's motion
direction
What is the single most important laboratory safety rule?
always follow intructions
What is the SI unit of speed?
meter per second
Is the unit of speed a basic unit or a derived unit?
derived unit
What can you say about the motion of a body if:
Its displacement-time graph is a straight line inclined with the time axis.
the body moves with uniform motion
What can you say about the motion of a body if
Its velocity-time graph is a straight line inclined with the time axis
the body moves with uniform acceleration
What can you say about the motion of a body if Its velocity-time graph is a parabola
the body moves with a non uniform motion
What conclusions can be drawn if a velocity-time graph is parallel to the time axis?
the body is moving with uniform velocity; its acceleration is 0; its displacement can be found by finding the area of the graph
What conclusions can be drawn if a velocity-time graph is a curve?
the body has a variable velocity and variable acceleration; the area under the curve represents displacement; accelration at any instant can be found by finding the slope at the point
What is the significance of the slope in a distance-time graph?
the slope is the change in distance divided by time, which gives speed
What types of changes in motion cause acceleration?
changes in speed and direction
What information does the slope of a speed-time graph provide?
acceleration
How is displacement different from distance? Under what conditions can an object travel a certain distance and yet its resultant displacement be zero?
displacement is vector and distance is scalar; when an object starts moving from a certain point and after covering certain distance returns to its starting position, its displacement becomes 0
How can you double the acceleration of an object if you cannot alter the object's mass?
double the net force acting on the object
During a collision, a seat belt slows the speed of a crash-test dummy. What is the direction of the net force exerted by the seat belt compared to the direction of the dummy's motion?
the direction of the net force is opposite the direction of the dummy's motion
How are the size and direction of action-reaction forces are related?
equal is size, opposite in direction
Why don't action-reaction forces cancel each other?
the action force and the reaction force act on different objects
Compare the speed of a moving golf ball with the speed of a moving bowling ball if both balls have the same amount of momentum
the speed of the golf ball is much greater than the speed of the bowling ball