Force and Motion Flashcards
(73 cards)
1
Q
- a push or a pull
- an agent that alter the velocity of a body by changing its speed or direction
A
force
2
Q
basic forces in nature
A
- gravitational force
- electromagnetic force
- strong nuclear force
- weak nuclear force
3
Q
force of attraction that acts over a large distance
A
gravitational force
4
Q
electric and magnetic interaction fused into a single interaction
A
electromagnetic force
5
Q
exist between nuclear particles ; the nuclear binding force; a short ranged force
A
strong nuclear force
6
Q
responsible for the very slow nuclear decay processes (radioactivity) like beta decay of the neutron
A
weak nuclear force
7
Q
classification of forces
A
- effects on motion (efforts)
- line of action
- relation to work
- interaction of bodies
8
Q
produce no motion or motion with constant velocity
A
balanced forces
9
Q
produce accelerated motion
A
unbalanced forces
10
Q
may go in the same direction or in opposite direction
A
parallel forces
11
Q
those that met at a point
A
concurrent forces
12
Q
can do work and can be stored as energy
A
conservative forces
13
Q
can do work but cannot be stored
A
non-conservative forces
14
Q
when an object is pushed by another, the two bodies are in contact with each other
A
contact force
15
Q
- force may act at a distance
- there is no contact between the body exerting the force and the body being acted upon
A
distant force
16
Q
continuous change in position with reference to a fixed point
A
motion
17
Q
branch of physics concerned with the study of motion and what produces and affect it
A
mechanics
18
Q
deals with the description of motion of objects without consideration of what causes the motion (quantitative)
A
kinematics
19
Q
analysis of the causes of motion
A
dynamics
20
Q
2 important aspects of motion
A
- a change of position or displacement
- the passage of time
21
Q
- a measurement of how fast one is moving
- defined as distance per unit time
A
speed
22
Q
speed accompanied with direction
A
velocity
23
Q
rate at which the motion was changed
A
acceleration
24
Q
a body that is not in uniform motion is said to be _____
A
accelerating
25
a state of fall under the influence of only gravity- free from air resistance
free-fall
26
average value of free-fall's acceleration
9.8 m/s squared
27
3 conditions wherein acceleration occurs
- change in the magnitude of the object's velocity, or change in speed
- change in direction of the object's velocity
- both change in speed and velocity
28
Newton's Laws of Motion
- law of inertia
- law of acceleration
- law of interaction
29
measure of the inertia of an object
mass
30
force of gravity on the object
weight
31
the change in the state of motion of objects is caused by a _____
net force
32
resistance of an object to changing its state of rest or state in motion/to continue moving at uniform velocity
inertia
33
“Any object will continue in its state of rest or uniform velocity unless acted on by a net force”
law of inertia
34
“When acted on by a net force, an object will accelerate proportional to the amount of the net force”
law of acceleration
35
SI unit of acceleration
Newton
36
proportional to the net force and inversely proportional to the mass of the object
acceleration
37
“To every action there is an equal and opposite reaction”
law of interaction
38
“Every particle in the universe attracts every other particle in the universe with a force that is proportional to the product of the two particles’ masses and inversely proportional to the square of the distance between them”
law of universal gravitation
39
state of balance
equilibrium
40
- bodies which are **at rest**
- **no motion** is produced
static equilibrium
41
body that **moves** with uniform motion
dynamic equilibrium
42
states of equilibrium
- stable
- unstable
- neutral
43
stability of an object is affected by the:
- position of the center of gravity (lower)
- area of the base (larger)
- weight of the object (greater)
44
conditions for equilibrium
- translational / force equilibrium
- rotational / torque equilibrium
45
"At equilibrium, the forces are such to cancel one another out" or "The **sum of all the forces** is equal to zero"
translational / force condition
46
"The **sum of the torques** acting on an object, as calculated about any axis, must be zero"
rotational / torque condition
47
a torque that tends to rotate the object **counterclockwise** is usually considered _____
positive
48
a torque that tends to rotate the object **clockwise** is usually considered ____
negative
49
- force that **opposes motion**
- parallel to the surface which are in contact
friction
50
types of friction
- static friction
- kinetic friction
51
friction between two surfaces that are **not sliding** relative to each other
static friction
52
friction between surfaces that are **sliding** over one another
sliding friction
53
friction between two surfaces when one surface is **rolling** over another
rolling friction
54
ratio of the friction force to the normal force passing the two surfaces together
coefficient of friction
55
_____ and _____ cause the change in the shape or motion of an object
- gravity
- friction
56
- Acts even at a distance
- Strength of the force is dependent on the distance between the objects and mass
- Reduced by decreasing the masses of objects and /or increasing the distance between them
- Directed toward the center of the object
gravity
57
- Present only when the two surfaces are in contact
- Depends on the nature and roughness of the surface in contact and masses of objects rubbing each other
- Reduced by lubricants and improving the smoothness of the rubbing surfaces
- Direction is opposite the direction of the motion of the object and perpendicular to the surface of contact
friction
58
an object or body thrown with an initial velocity and whose motion is influenced by the pull of gravity
projectile
59
Objects that are initially thrown horizontally in space will be acted upon by gravity thus will move in x and y directions simultaneously.
projectile motion
60
path of the projectile
trajectory
61
2 types of motion determined by trajectory
- vertical motion
- horizontal motion
62
an object travelling in a circle at constant speed is said to be undergoing a _______
uniform circular motion
63
time required for an object to make one complete revolution
period
64
number of revolutions completed by the object in a given time
frequency
65
device which separates the lighter and heavier substances in a mixture
centrifuge
66
suggests that the force of gravity acting between any two objects is inversely proportional to the square of the separation distance between the object's center
inverse square law
67
German astrologer who preceded Newton's law of gravitation
Johannes Kepler
68
Kepler's laws of planetary motion
- law of orbits
- law of areas
- law of periods
69
"The planet then follows the ellipse in its orbit, which means that the Earth-Sun distance is constantly changing as the planet earth goes around its orbit"
law of orbits
70
point of nearest approach of the planet to the Sun
perihelion
71
point of greatest separation
aphelion
72
By Kepler's ____ law, the planet moves fastest when it is near perihelion and slowest when it is near aphelion
second (Law of Areas)
73
Kepler's ____ Law implies that the period for a planet to orbit the Sun increases rapidly with the radius of its orbit.
third (Law of Periods)
