[General] Chit Chat Corner

[mepkoh]

can speed be negative?

 

reversing? do u identify this as negative?

 

what about deceleration? as compared to acceleration?

 

ascending and descending?

 

qed

[kmax]

vidak really gone case liao..

[thenation]

I thought you mentioned him before... when I went to SMU that day wasn't the excuse about helping him for a presentation...?

 

Er don't think so...anyway I don't remember what name I gave as an excuse and I don't have any profs by that name...

[jtzx]

hmm... Maths Lesson in this thread. die liao die liao.. I'm gonna faint after seeing so much XX yy...

[Kevs]

well.. i been here 3 years and vidak has over taken most of us..

 

so how can you say such to me

 

he's trying to catch up Encik pat i guess..

 

heheh...

welcome to the reality my fren...

 

me so devoted type... one at a time.. may be one after another..

 

so contradicting...

 

ok fine... I will rephrase the question a little bit...

 

VidaK finds that travelling at x speed along KPE is perfectly alright along the entire length of KPE. Find x.

 

You are given that (x² - 81x - 186) cos [(π/2) - 90°] = 0, where x is > 0, and π is pi.

 

SMLS!

oei, chit chat thread leh, mai di di input unsolvable-terrrible-horrible-incorrigible-FKNNCCB-~!@#$%^&*()(*&^%$#@!~ maths or formulae here leh...

 

 

boomz:dot:

[lunloon]

can speed be negative?

 

reversing? do u identify this as negative?

 

what about deceleration? as compared to acceleration?

 

ascending and descending?

 

qed

 

Nope. Speed being linear cannot be negative.

Velocity can, as a vector, that's where reversing = negative velocity.

Deceleration and acceleration is not speed. It's the rate of change of speed wrt time. Can be negative (deceleration) and positive (acceleration).

 

Ascending happens when one get's run over, without any cure, and that he has been doing good deeds. Decending is when the same guy has been evil for very long.

 

[mepkoh]

i am confused...so many defn.

 

Noun 1. speed - distance travelled per unit time

velocity

angular velocity - (physics) the rate of change of the angular position of a rotating body; usually expressed in radians per second or radians per minute

airspeed - the speed of an aircraft relative to the air in which it is flying

escape velocity - the minimum velocity needed to escape a gravitational field

groundspeed - the speed of an aircraft relative to the ground

hypervelocity - excessive velocity; "the meteorites struck the earth with hypervelocity impacts"

muzzle velocity - the velocity of a projectile as it leaves the muzzle of a gun

peculiar velocity - velocity with respect to the local standard of rest

radial velocity - velocity along the line of sight toward or away from the observer

light speed, speed of light, c - the speed at which light travels in a vacuum; the constancy and universality of the speed of light is recognized by defining it to be exactly 299,792,458 meters per second

steerageway - (nautical) the minimum rate of motion needed for a vessel to be maneuvered

terminal velocity - the constant maximum velocity reached by a body falling through the atmosphere under the attraction of gravity

rate - a magnitude or frequency relative to a time unit; "they traveled at a rate of 55 miles per hour"; "the rate of change was faster than expected"

2. speed - a rate (usually rapid) at which something happens; "the project advanced with gratifying speed"

fastness, swiftness

pace, rate - the relative speed of progress or change; "he lived at a fast pace"; "he works at a great rate"; "the pace of events accelerated"

haste, hastiness, hurriedness, hurry, precipitation - overly eager speed (and possible carelessness); "he soon regretted his haste"

execution speed - (computer science) the speed with which a computational device can execute instructions; measured in MIPS

graduality, gradualness - the quality of being gradual or of coming about by gradual stages

3. speed - changing location rapidly

hurrying, speeding

movement, move, motion - the act of changing location from one place to another; "police controlled the motion of the crowd"; "the movement of people from the farms to the cities"; "his move put him directly in my path"

speedup, acceleration, quickening - the act of accelerating; increasing the speed

deceleration - the act of decelerating; decreasing the speed; "he initiated deceleration by braking"

scud, scudding - the act of moving along swiftly (as before a gale)

4. speed - the ratio of the focal length to the diameter of a (camera) lens system

f number, focal ratio, stop number

ratio - the relative magnitudes of two quantities (usually expressed as a quotient)

5. speed - a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression

amphetamine, pep pill, upper

amphetamine sulfate, amphetamine sulphate - a sulfate derivative of amphetamine that is used as a stimulant for the central nervous system

bennie, Benzedrine - a form of amphetamine

Dexedrine, dextroamphetamine sulphate - an isomer of amphetamine (trade name Dexedrine) used as a central nervous system stimulant

drug of abuse, street drug - a drug that is taken for nonmedicinal reasons (usually for mind-altering effects); drug abuse can lead to physical and mental damage and (with some substances) dependence and addiction

deoxyephedrine, meth, methamphetamine, methamphetamine hydrochloride, Methedrine, shabu, chicken feed, crank, chalk, trash, glass, ice - an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant

excitant, stimulant drug, stimulant - a drug that temporarily quickens some vital process

Verb 1. speed - move fast; "He rushed down the hall to receive his guests"; "The cars raced down the street"

belt along, bucket along, cannonball along, hie, hotfoot, pelt along, race, rush, rush along, step on it, hasten

go, locomote, move, travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast"

barge, push forward, thrust ahead - push one's way; "she barged into the meeting room"

shoot down, tear, buck, charge, shoot - move quickly and violently; "The car tore down the street"; "He came charging into my office"

dash, scoot, scud, dart, flash, shoot - run or move very quickly or hastily; "She dashed into the yard"

accelerate, quicken, speed up, speed - move faster; "The car accelerated"

2. speed - move faster; "The car accelerated"

accelerate, quicken, speed up

brisk, brisk up, brisken - become brisk; "business brisked up"

deepen, intensify - become more intense; "The debate intensified"; "His dislike for raw fish only deepened in Japan"

3. speed - move very fast; "The runner zipped past us at breakneck speed"

hurry, travel rapidly, zip

go, locomote, move, travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast"

dart, fleet, flit, flutter - move along rapidly and lightly; skim or dart; "The hummingbird flitted among the branches"

run - move fast by using one's feet, with one foot off the ground at any given time; "Don't run--you'll be out of breath"; "The children ran to the store"

whizz along, zoom, zoom along, whizz - move along very quickly

accelerate, quicken, speed up, speed - move faster; "The car accelerated"

4. speed - travel at an excessive or illegal velocity; "I got a ticket for speeding"

go, locomote, move, travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast"

5. speed - cause to move faster; "He accelerated the car"

accelerate, speed up

alter, change, modify - cause to change; make different; cause a transformation; "The advent of the automobile may have altered the growth pattern of the city"; "The discussion has changed my thinking about the issue"

[thenation]

Wah uncle koh. I see liao eyes abit pain. What lun means is that speed is just a value as it does not indicate the direction you're moving in. So you may be reversing your car at 20km/h but your speed is still 20 km/h and not -20km/h. BUT your velocity is -20km/h because velocity takes into account the direction you're moving in.

 

Nice one about ascending and descending lun haha!

[VidaK]

vidak really gone case liao..

 

no I'm not...

 

Er don't think so...anyway I don't remember what name I gave as an excuse and I don't have any profs by that name...

 

awww... ok... lol...

 

hmm... Maths Lesson in this thread. die liao die liao.. I'm gonna faint after seeing so much XX yy...

 

aiya... ok fine... after my econs lecture when I come back I will show you all the answers... pfftttt...

[mepkoh]

Wah uncle koh. I see liao eyes abit pain. What lun means is that speed is just a value as it does not indicate the direction you're moving in. So you may be reversing your car at 20km/h but your speed is still 20 km/h and not -20km/h. BUT your velocity is -20km/h because velocity takes into account the direction you're moving in.

 

Nice one about ascending and descending lun haha!

hahaha..

the only speed that comes to mind is the stuff that we should avoid at all cost..

 

hoho..either with your bike or in your tummy...

Edited October 22, 2009 by mepkoh

[mepkoh]

okay..so speed is not velocity...okay..understood.

so where is vidak going??--..

 

 

VidaK finds that travelling at x speed along KPE is perfectly alright along the entire length of KPE. Find x.

 

You are given that (x² - 81x - 186) cos [(π/2) - 90°] = 0, where x is > 0, and π is pi.

____

the primary maths is getting too complicated for me...

i just have to learn my times table when i sat for that exam...

[arjen]

wall of text

 

+ 999 damage.

[kmax]

so contradicting...

 

phantom -> super4 -> TDM... one by one what...

[VidaK]

ok fine... I will rephrase the question a little bit...

 

VidaK finds that travelling at x speed along KPE is perfectly alright along the entire length of KPE. Find x.

 

You are given that (x² - 81x - 186) cos [(π/2) - 90°] = 0, where x is > 0, and π is pi.

 

(x² - 81x - 186) cos [(π/2) - 90°] = 0

 

(x² - 81x - 186) cos [(180°/2) - 90°] = 0

 

(x² - 81x - 186) cos (90° - 90°) = 0

 

(x² - 81x - 186) cos 0° = 0

 

(x² - 81x - 186) (1) = 0

 

x² - 81x - 186 = 0

 

(x - 83) (x + 2) = 0

 

therefore x = 83 or x = -2

 

since it is given that x is > 0, x = 83

 

[Magg]

(x² - 81x - 186) cos [(π/2) - 90°] = 0

 

(x² - 81x - 186) cos [(180°/2) - 90°] = 0

 

(x² - 81x - 186) cos (90° - 90°) = 0

 

(x² - 81x - 186) cos 0° = 0

 

(x² - 81x - 186) (1) = 0

 

x² - 81x - 186 = 0

 

(x - 83) (x + 2) = 0

 

therefore x = 83 or x = -2

 

since it is given that x is > 0, x = 83

 

 

:thumb:

 

HAHA vidak, you really have so much time in your hands to come up with this formula?

 

LOL Just tell us that you were traveling at 83 km/h in KPE, and Kmax wouldn't think that you are crazy, joshua wouldn't faint, Kev wouldn't be irritable, mepkoh wouldn't be confused, and lun wouldn't have to explain/clarify the theory of acceleration, deceleration, and negative speed velocity

 

See. Save all that trouble and damage

[VidaK]

:thumb:

 

HAHA vidak, you really have so much time in your hands to come up with this formula?

 

LOL Just tell us that you were traveling at 83 km/h in KPE, and Kmax wouldn't think that you are crazy, joshua wouldn't faint, Kev wouldn't be irritable, mepkoh wouldn't be confused, and lun wouldn't have to explain/clarify the theory of acceleration, deceleration, and negative speed velocity

 

See. Save all that trouble and damage

 

its meant for thenation ma... then he didn't quite attempt it...

 

anyway... join us to purge the devil... 1DTO Vs PK

[jtzx]

man... What maths is this? A maths?? haha.. So chim for me.. My poly lecturer not yet taught me lehz...

[VidaK]

man... What maths is this? A maths?? haha.. So chim for me.. My poly lecturer not yet taught me lehz...

 

its... sec 3 e.maths...

[jtzx]

its... sec 3 e.maths...

 

lolz.. think i returned everything to teacher liao..

[VidaK]

lolz.. think i returned everything to teacher liao..

 

haha its ok...

 

NO its not ok... you better study hard!!

[jtzx]

haha its ok...

 

NO its not ok... you better study hard!!

 

 

haha.. engineering lehz.. suppsely maths should be beri zai de.. But abit sot sot lehz..

 

 

haha.. my computer programming teaching now keep on talking.. ZZzzzz:sian:

[Kevs]

phantom -> super4 -> TDM... one by one what...

 

oh.. OH...

i was reading the words inbetween the lines...

 

(x² - 81x - 186) cos [(π/2) - 90°] = 0

 

(x² - 81x - 186) cos [(180°/2) - 90°] = 0

 

(x² - 81x - 186) cos (90° - 90°) = 0

 

(x² - 81x - 186) cos 0° = 0

 

(x² - 81x - 186) (1) = 0

 

x² - 81x - 186 = 0

 

(x - 83) (x + 2) = 0

 

therefore x = 83 or x = -2

 

since it is given that x is > 0, x = 83

 

 

basket.

i noe i did this before, but eyes & brain cannot process in this forum here:dot:

 

:thumb:

 

HAHA vidak, you really have so much time in your hands to come up with this formula?

 

LOL Just tell us that you were traveling at 83 km/h in KPE, and Kmax wouldn't think that you are crazy, joshua wouldn't faint, Kev wouldn't be irritable, mepkoh wouldn't be confused, and lun wouldn't have to explain/clarify the theory of acceleration, deceleration, and negative speed velocity

 

See. Save all that trouble and damage

 

thnx magg...

 

its... sec 3 e.maths...

 

wtf?

u mean they teach this is sec 3 nowadays?

omfg...

no wonder when i started my p/t dip, i was lost-aghasted-flabbergasted-shock-angry-cursing all the way till after the exams...

[VidaK]

oh.. OH...

i was reading the words inbetween the lines...

 

 

 

basket.

i noe i did this before, but eyes & brain cannot process in this forum here:dot:

 

 

 

thnx magg...

 

 

 

wtf?

u mean they teach this is sec 3 nowadays?

omfg...

no wonder when i started my p/t dip, i was lost-aghasted-flabbergasted-shock-angry-cursing all the way till after the exams...

 

ha... oops...

[thenation]

(x² - 81x - 186) cos [(π/2) - 90°] = 0

 

x² - 81x - 186 = 0

 

(x - 83) (x + 2) = 0

 

therefore x = 83 or x = -2

 

since it is given that x is > 0, x = 83

 

 

Haha this is the way I would have done it. The cos part is a constant so there's no need to reduce it down.

[jtzx]

wtf?

u mean they teach this is sec 3 nowadays?

omfg...

no wonder when i started my p/t dip, i was lost-aghasted-flabbergasted-shock-angry-cursing all the way till after the exams...

 

haha.. relax... i nr learnt A maths my sec skool also.. come to poly, almost die.. The maths alone can give me stress liao...

 

what dip you doing kev?