Physics Unit Exam

Question 1

what is sigdig short for?

Answer 1

significant digits

Question 2

do non-zero numbers count towards sigdigs?

Answer 2

YES!

Question 3

do leading zeros count towards sigdigs?

Answer 3

NO!!!

Question 4

do in-between zeros count towards sigdigs?

Answer 4

YES!

Question 5

do trailing zeros count towards sigdigs?

Answer 5

YES!

Question 6

how do you put something in scientific notation?

Answer 6

-move the decimal to after the first non-zero digit
-like usual, cut and round
-we need to account for the fact that we moved the decimal! to do this, add 10 to the exponent of how many times we moved the decimal.
ex. 12345678=1.23x10^7

Question 7

how many meters is in a kilometre?

Answer 7

1000

Question 8

how many millilitres is in a litre?

Answer 8

1000

Question 9

what is uniform motion?

Answer 9

moving at a constant rate in the same direction

Question 10

what is average speed?

Answer 10

a change in distance over a given time interval
v=d/t

Question 11

what does the slope on a distance-time graph represent?

Answer 11

speed!

Question 12

what does the steepness of a slope tell us?

Answer 12

how fast the object is moving

Question 13

what does the area on a speed-time graph represent?

Answer 13

distance

Question 14

how do we calculate slope?

Answer 14

x2-x1

Question 15

what is a scalar quantity and what is an example?

Answer 15

have a magnitude only; no direction associated with it.
ex. time, mass, distance, speed, energy, work

Question 16

what is a vector quantity and what is an example?

Answer 16

have both magnitude and direction
ex. displacement, velocity, force, acceleration, deceleration

Question 17

what is a position?

Answer 17

the separation between an object and its starting point

Question 18

what does magnitude mean?

Answer 18

size/amount of/how many

Question 19

is distance a scalar or a vector quantity?

Answer 19

SCALAR!

Question 20

is displacement a scalar or a vector quantity?

Answer 20

VECTOR!

Question 21

what is the navigator method?

Answer 21

ex. 30 degrees north of east

Question 22

what is the Cartesian method?

Answer 22

ex. 97 degrees north of east

Question 23

what is average velocity?

Answer 23

a change in position over a certain time
v=d/t

Question 24

what does the slope on a position-time graph represent?

Answer 24

velocity!

Question 25

what is acceleration?

Answer 25

the change in velocity during a given time interval a=Vf-Vi/t

Question 26

what is acceleration measured in?

Answer 26

m/s^2

Question 27

what does the area on a velocity-time graph represent?

Answer 27

displacement

Question 28

what is a force?

Answer 28

a push or pull mass x acceleration

Question 29

what is force measured in?

Answer 29

newtons(N)

Question 30

what is mass?

Answer 30

the amount of matter that makes up an object measured in kg

Question 31

what is weight?

Answer 31

the force exerted on an object by gravity measured in newtons(N)

Question 32

what does the area under a force-displacement graph represent?

Answer 32

work!

Question 33

what is Newton's first law of motion?

Answer 33

in the absence of a net force, an object in motion will maintain its velocity, and an object at rest will stay at rest.

Question 34

what is the formula for work?

Answer 34

W=fd

Question 35

what is work?

Answer 35

transfer of energy from one object to another

Question 36

what is energy?

Answer 36

the ability to do work

Question 37

true or false: work is always equal to energy

Answer 37

TRUE!

Question 38

what are the three things that must happen for work to have been done?

Answer 38

1) the object must move some distance 2) a force must be applied 3) the direction of movement must be in the same direction as the applied force

Question 39

what are the 4 common types of kinetic energy?

Answer 39

electrical, thermal, light, and sound

Question 40

what are the 4 common types of potential energy?

Answer 40

chemical, elastic, nuclear, and gravitational

Question 41

what is the speed of gravity?

Answer 41

9.81 m/s^2

Question 42

what is mechanical energy?

Answer 42

the sum of an object's energy (kinetic+potential)

Question 43

what is the first law of thermodynamics?

Answer 43

energy cannot be created nor destroyed. only converted from one form to another

Question 44

what is the second law of thermodynamics?

Answer 44

no energy conversion is 100% efficient, some energy is always lost as heat when converting from one form to another.

Question 45

what is efficiency?

Answer 45

a measurement of how much energy input a machine converts into useful output energy