Forces And Motion

Front 1

change of an object's position in time / displacement over time

Back 1

motion

Front 2

graph of general motion in one dimension

Back 2

y-axis: position (d)
x-axis: time (t)

Front 3

the change in an object's position and is measured in units of length

Back 3

displacement

Front 4

1. has magnitude and direction
2. Examples are displacement, velocity, acceleration

Back 4

vector quantity

Front 5

1. how rapidly the position of the object (d) changedover the time interval (t)
2. measured in m/s and mph
3. v = d/t = (d2-d1)/(t2-t1)
4. a vector quantity

Back 5

average velocity

Front 6

a measure of average velocity over smaller and smaller time intervals

Back 6

instanteneous velocity

Front 7

1. velocity (v) of an object over a time interval (t)
2. measured in m/s2
3. a = (v2-v1)/(t2-t1)
4. a vector quantity

Back 7

acceleration

Front 8

equations for uniform acceleration

Back 8

1. v = d/t
2. v = (vi + vf)/2
3. vf = vi + a.t
4. d = vi.t + 1/2.a.t2; vi = 0 start rest
5. vf2 = vi2 + 2.a.d

Front 9

acceleration due to gravity

Back 9

9.8 m/s2

Front 10

Position-Time Graphs

Back 10

1. Position in meters (y) and Time in seconds (x)
2. d/t

Front 11

1. a push or pull in a given direction
2. has both magnitude (size) and direction

Back 11

force (F)

Front 12

1. Hooke's law
2. magnitude of a F is directly proportional to the elongation or compression of a spring (x)

Back 12

Fs = k.x
where Fs is measured in Newtons
k is the spring constant (N/m)
x is elongate/compress (m)

Front 13

1. SI unit of Force
2.force required to accelerate a 1-kg mass at a rate of 1 m/s2

Back 13

Newton

Front 14

the sum of many fores that act on an object

Back 14

resultant force

Front 15

when the net force is zero, the object is in ________________

Back 15

equilibrium

Front 16

Newton's first law?

Back 16

1. Law of inertia
2. All objects remain in their state of rest, or in motion in a straight line, unless acted upon by an outside force.
3. in equilibrium

Front 17

Newton's second law?

Back 17

1. Law of constant acceleration
2.Force is equal to the product of mass and acceleration or F = m.a
3. N = kg.m/s2

Front 18

forces exerted on pilots and astronauts when they are accelerated at rates higher than the acceleration of gravity

Back 18

g-force

Front 19

Newton's third law?

Back 19

1. Law of Momentum
2. For each action, there is an equal and opposite reaction

Front 20

Newton posited that all objects with mass exert an attractive force on all other objects with mass, and that this force is directly proortional to the product of the masses of the two objects and inversely proportional to their distance squared.

Back 20

1. Newton's law of universal gravitation
2. FG = (Gm1.m2)/r2
where G is gravitational constant
m1 & m2 masses of objects
r2 distance between objects
3. The value of G is 6.67 x 10-11 (N.m2)/kg2

Front 21

the ratio of the force exerted per unit is ______________

Back 21

pressure

Front 22

formula for pressure

Back 22

Pressure = Force/Area

where Pressure (P) = Pascal (Pa)
Force (F) = Newton
Area (a) = square meters

Front 23

the formula for pressure at some depth in a liquid of a given density is ____________

Back 23

Pressure = D x g x h

where D is density
g is acceleration of gravity
h is the depth of the liquid

Front 24

the upward pressure of liquids to an object is _______________

Back 24

buoyant force / buoyancy

Front 25

what is archimedes' principle?

Back 25

the buoyant force exerted on an object is equal to the weight of the volume if liquid displaced

Front 26

what forces affect a fish swimming underwater?

Back 26

(downward force) weight (gravity), pressure of liquid above and (upward force) buoyant force

Front 27

What causes surface tension in water?

Back 27

Surface tension occurs in water because they are polar. The hydrogen atom side is slightly positive and the oxygen side is slightly negative causing attractive forces on one another and other polar molecules.

Front 28

One atmosphere is equivalent to _________________

Back 28

1.013 x 10^5 N/m^2

Front 29

what is blood pressure?

Back 29

Blood pressure is the force in the arteries when the heart beats (systolic pressure) and when the heart is at rest (diastolic pressure). High blood pressure or hypertension is >=140 mm Hg (sys) and >=90 mm Hg (dias).

Front 30

How does salt cause hypertension?

Back 30

Excessive salt keeps the circulatory volume higher than it should be, exerting excess fluid pressure on blood vessel walls. These walls react to this stress by thickening and narrowing, leaving less space for the fluid already cramped in the blood compartment, raising “resistance” and requiring higher pressure to move blood to the organs. The heart's 24/7 activity can cause the heart to enlarge. The kidney contains around one million tiny, delicate filters comprised of blood vessels (nephrons). The increase in pressure transmitted to the kidneys damages its vascular system leading to a disorder known as “hypertensive nephrosclerosis”.

Front 31

the force that holds protons together in the nucleus of an atom

Back 31

strong nuclear force

Front 32

What are the four known forces in the universe?

Back 32

Gravity, electromagnetic force, nuclear force,

Front 33

the force related to the stability of the neutron itself

Back 33

weak nuclear force

Front 34

the force that holds the electrons and the protons together

Back 34

electromagnetic force

Front 35

what is beta decay?

Back 35

neutron --> proton + electron (beta particle) + antineutrino

Front 36

what is alpha decay?

Back 36

atomic number decreases by 2 (2 protons are ejected) and the atomic mass number by 4 (2 neutrons are also ejected)

Front 37

what is beta plus decay?

Back 37

Protons decays to become a neutron plus a positron (a particle with the same mass as an electron but with a positive charge; antiparticle of electron; POSItive elecTRON) and an electron-type neutrino ( a particle with little or no mass and no charge)

Front 38

a device that allows work to be done and offers an advantage to the user

Back 38

simple machine

Front 39

equation for ideal mechanical advantage (IMA)

Back 39

F in.d in = F out.d out

F in/F out = d out/d in

because of friction, there is actual mechanical advantage (AMA)

Front 40

equation for the efficiency of a machine

Back 40

Efficiency = AMA/IMA = %

Front 41

examples of simple machines

Back 41

inclined planes, pulleys, levers, wheels and axles and screwdrivers

Front 42

the product of force and the component of displacement is called ___________

Back 42

1. work - should be at the same direction
2. newton.meter or joule (J)
3. scalar quantity

Front 43

the rate at which work is done is called _______________

Back 43

power