PHYSICS 211 Exam 1

meter m

What is the SI unit of length and its abbreviation?

second s

What is the SI unit of time and its abbreviation?

kilogram kg

What is the SI unit of mass and its abbreviation?

Kelvin K

What is the SI unit of temperature and its abbreviation?

mole mol

What is the SI unit of amount of substance and its abbreviation?

ampere A

What is the SI unit of electric current and its abbreviation?

candela cd

What is the SI unit of luminous intensity and its abbreviation?

tera T

trillion 10^12

giga G

billion 10^9

mega M

million 10^6

kilo k

thousand 10^3

deci d

tenth 10^-1

centi c

hundredth 10^-2

mili m

thousandeth 10^-3

micro u

millionth 10^-6

nano n

billionth 10^-9

pico p

trillionth 10^-12

accuracy

how close your measured value is to known value

precision

how consistent your measurements are

same as least significant

How many digits should your answer have when multiplying or dividing?

same decimal places as value with least

How many digits should your answer have when adding or subtracting?

vector

quantity with magnitude and direction

mechanics

study of relationship between force and motion

Galileo's Law of Falling

law; two objects dropped from same height will fall together and hit the ground at the same time

air resistance

resistance to the motion of an object through air due to the object's collisions with numerous air molecules

inertia

object's tendency to maintain its state of motion

Newton's First Law of Motion

law; body at rest tends to remain at rest and a body in motion tends to maintain its motion

kinematics

classification and comparison of motions

vector

Is displacement vector or scalar?

m/s

What is the SI unit for velocity and speed?

acceleration

change in velocity

speeding, positive

if velocity > 0 and acceleration > 0 then the particle is ________ in the _______ direction

slowing, positive

if velocity > 0 and acceleration is < 0 then the particle is _______ in the ______ direction

speeding, negative

if velocity < 0 and acceleration is <0 then the particle is _______ in the _________ direction

slowing, negative

if velocity < 0 and acceleration is > 0 then the particle is _____ in the ________ direction

increases

if acceleration and velocity have the same sign then the speed ___________

velocity

can be found by looking at the area on the acceleration vs time graph

velocity

slope of the position v. time graph tells ______

acceleration

slope of a velocity v time graph tells ________

displacement

can be found by looking at the area on the velocity v. time graph

true

True or False: any two objects in the free fall, regardless of their mass, density, or shape

dynamics

explaining why things move as they do

force

external influence that causes an object to accelerate

Newton's Second Law of Motion

body's acceleration is directly proportional to the net force acting on it and inversely proportional to the body's mass (a=F/m)

false

True or False: If an object's acceleration is zero, the object must be stationary.

False

True or False: When a ball thrown upward reaches its highest point, its ACCELERATION is zero.

True

True or False: When a ball thrown upward reaches its highest point, its VELOCITY is zero.

True

True or False: If the slope of a plot of position versus time is changing, the object is undergoing acceleration.

False

True or False: If the slope of a plot of velocity versus time is constant, the object cannot be moving.

True

True or False: If you travel at 70 mi/hr from Fargo to Minneapolis, MN, and then return to Fargo at the same speed, your average velocity for the trip is zero.

False

True or False: The magnitude of the sum of two vectors must be greater than the magnitude of either vector.

False

True or False: If the speed is constant, the acceleration must be zero.

True

True or False: If the acceleration is zero, the speed must be constant.

False

True or False: If an object's speed does not change, no net force is acting on the object.

False

True or False: If two different objects are under the influence of equal forces, they will have equal accelerations.

True

True or False: The net force acting on an object that remains at rest is zero.

True

True or False: If a net force acts on an object, the object's velocity will change

True

True or False: The net force acting on an object that maintains a constant velocity is zero

False

True or False: In order to not slow down, an object moving at a constant velocity needs a small net force applied.

system

part of the universe of interest to us

external force

any force on the bodies inside a system from bodies outside the system