₦airaland Forum

Simplefemo: v=3u
1/3u+ 1/u=1/15
1+3/3u=1/15
60=3u
u=20cm
object distance, u= 20cm

U are wrong my guy.

Attempt this:

A certain far-sighted person cannot see objects that are closer to the eye than 50cm clearly. Determine the power of the converging lens which will enable him to see at 25cm.

Attempt this:

An image in a convex lens is upright and magnified 3 times. If the focal length of the lens is 15cm, what is the object distance?

t.boy007:
1)Which of there undergoes condensation reaction
a)alkanol
b)amine
c)alkanal
d)haloalkane

Am biased towards option a) cos when they react with carboxylic or alkanoic acids they give out water. Is that correct?

t.boy007:
A particle in a straight line specified by the equation y=4t^4 - 3t^3.find the acceleration after 3 seconds.

Velocity(v) of the particle = dy/dt = 4x4xt^3 - 3x3xt^2, v = 16t^3 - 9t^2.
Acceleration(a) of the particle = dv/dt = 16x3xt^2 - 9x2xt, a = 48t^2 - 18t., but t = 3seconds, hence:
a = 48(3^2) - 18x3, a = 48x9 - 18x3, a = 432 - 54, a = 378m/s

therefore the acceleration of the particle is 378m/s.
My 2cent on the question.

t.boy007:
2)which of the following react with NaOH to give double salts?
a)S02
b)S03
c)P04
d)N02

d)NO2,. This is because it is a mixed acid anhydride.

buzyguy: Hmm,u r vry rite.no wahala jamb z already in wahala ijn.we r all gonna mak it big!

Amen o. We are gonna hammer wella

buzyguy: Mag.=v/u,v z sam with u in distance from da mirror.so 10cm/10cm=1 no unit.i lyk dat level don chang we r nw on level ten over ten.lolz!

Bravo for ur good reasoning. You know, after solving the question the first time, i just told myself "wow! Jamb could be so tricky sometimes".

I think why some students fail exams thesedays is dawn to lack of composure in exam hall, rather than ignorance.
I keep asking God for this wonderful virtue called composure together with serenity. With them, i know i will keep blasting exams after exams.

Attempt this:

The magnification of an object tall when placed 10cm in front of plane mirror is

Good to be back after being absent for a while. Abi fynestboi don change to fynestbarrister or abi na another person?

t.boy007:
focal lenght=15
mirror's equation=>1/f=1/u + 1/v
since the image produced is 4 times the object.therefore 1v=4u.
So, 1/15=1/u + 1/4u
u=75/4
u=+18.75cm(since it's a concave mirror)

Gbam! You are On point.

Attempt this:

A concave mirror of radius of curvature 30cm produced an inverted image 4 times the size of an object placed perpendicular to the axis. Determine the position of the object.

Nemidav: o! Owk. . . Gudluck bro.

Thanks a bunch

Nemidav: yu too. . .tot ui is a federal uni??

Yea, it is. I learnt that they admit 2nd choice candidates.

buzyguy: Yeah,whr av u bn snce?u r 2correct!

I have been around my guy, but didn't know the existence of this thread. I just found it yesterday. Anyways, how is jacking going over there? The D day is almost close

buzyguy: Sum1 try ds,A Car of mass Mkg is accelratd uniformly frm rest by an engine power P.The minimum time it wil take to attain a speed V is,a.MV/P b.MV/2P c.MV^2/2P d.MV^2/P

My real guy nice to meet u here.
The answer to ur question is c).
Reason: the power of the accelerated car = energy expended by the car/time taken.
But in this case, the energy of the car is all kinetic.
Hence, power(P) = k.e/time(T), P = 1/2MV^2/T. Multiplying both sides by T.
PxT = 1/2MV^2/TxT, PT = 1/2MV^2. Divide both sides by P.
PT/P = 1/2MV^2/P,
Therefore, T = MV^2/2P.

Nemidav: thanks 4 d nice words . . . i'm goin 4 medicine,uniben. . . I filld d same tin last year bur i was 10% lower dan medicine's cutoff,i was given biology tho. . Bur i turned it down. . . . Wht about you?

Our good Lord will grant you your heart desire this year. Am going for electrical electronics engineering, futo is my 1st choice while ui is my 2nd. Nice to have u around here.

Nemidav: anoda method learnt,thanks

thanks alot. . I jst learnt sumfin very valuable 4rm yu.

Honestly, u are such a great guy. Very flexible and willing to learn. These are the qualities that are lacking among us the students, but am really challanged. If you don't mind, which course are u aspiring for and ur preferred institutions?

t.boy007:
wao @andrew,i've gained from that explanation of yours...
I think it can also be solved this way,
from the law of conservation of energy { F=Mv/t}
since f=30N,M=0.075kg,t=0.05
then make v the subject of the formula and solve.the final answer will be 20 N/s

U are on point my guy. If u multiply both sides of that ur equation by t, u wil get the same thing i used.

Nemidav: I jst messd up!. . .neva knew momentum was = impulse

I woud rather say that u made mistake, but didn't mess up. Come on! Nobody is perfect, we make mistakes everyday. Just keep the good work up.

Nemidav: thanks!

U are welcome

Nemidav: i solvd it lyk diz f=30N,T= 0.05S,M= 0.075kg,u=0...a=f/m;a=30/0.075;a=400
then i used s=ut+1/2at^2
s=1/2*400*0.0025
;s=0.5;using speed=distance/time;0.5/0.05=10. . . . And therez no 10 in d options,did i make a mistake?

Perhaps u were wrong. I think u unnecessarily prolonged a simple work.
Below is my little explanation to the question:

When a force f(N) is applied on a body of mass m(kg) for a given period of time t(s), the body gains momentum i.e, the massive body moves forward with a certain velocity. The gain in momentum is as a result of force which acts with time. With the already established fact, i can safely say that the gain in momentum is also as a result of impulse on the body. I believe u still remember that impulse is mathematically expressed as: force x time, ft. From law of conservation of energy, energy exhausted for exerted force on the body for a period of time = energy gained by the body to give it momentum.

Hence, impulse = momentum gained, i.e, ft = mv (where m=mass of the body, v = velocity gained. Of course, f is force and t is time taken)

Relating my explanation with the problem at hand, we have:

force exerted by the footballer = 30N, time taken = 0.05s, mass of ball = 0.075kg, velocity= ?.
Substituting:
30x0.05 = 0.075xV, 0.075V = 1.5 (divide both sides by 0.075)
0.075V/0.075 = 1.5/0.075
V = 20m/s.
Therefore, the velocity gained by the ball is 20m/s.

N:B, i only elaborated this much for u to understand what really happened, not that the question is really that difficult.

Hope that helps!

buzyguy: Mbbs,i already knw urz EEE rite?datz great,may God help us in 4 our desired coursez.AMEN! 1nce again am vry sori in all av gone wrong.thks!

Amen o! U are more than welcome my guy.

Tizzie: Enough of all this Bants,can we continue with the main reason for being on this thread already?

We were merely expressing our opinions to each other. It's really nothing serious. Busyguy is my real man. K?

buzyguy: i apologize 4 callin u a boy cuz evn kidz nw adayz reject such,letz bury da hatchet.peace! Itz A bro,mayb u didnt read it wel chck bak tru it.thkz

Apology accepted. I also sincerely tender my apology to you. I didn't mean to insult or debase ur integrity. We can stil be friends. Ehee! Before i forget, which course are u aspiring for? Nice weekend!

buzyguy: ltz nt a fight.ds thread z for a purpoze so let faze.

Fight? It's been more than decade i fought last and i can't imagine myself engaging in a fight with anyone.

buzyguy: so chang dat ur mentality,

Thank u for the advice, but.....

buzyguy: i shld say sumtn bt i dnt jst wonu offend any1 here ,

U have already written more than one page about a guy u've not met before.

buzyguy: i sense u r da one being discourteouz.

Perhaps that's ur opinion, but am really better than what you think of me. Am really a nice and easy-going guy.

buzyguy: if nt of my dream courz wich i stil av in mind,nd determd to pursue afta completn a degr i dnt fink i shld b here absorbn insultz frm an anönymouz fellow here.

Anonymous fellow? Adding insult to injury, yet u feign a gentleman. My name is Andrew and not anonymous fellow.

buzyguy: i wz silent cuz i knw itz nairaland tnz nd u r free to say worefa u wish here.wot do think?

Hell no! U weren't silent, rather u doubled the supposed insult. I also differ with u there. One is not entitled to say what one wants provided that it's deflamatory to other people's integrity or personality.( I myself, is not excepted to that).

buzyguy: do u rememba ur quote dat i mak a baseless argument,of courz datz 2ridiculouz 2my persnalty..

I was just trying to let u know that u needed to back ur argument with proof,cos i thought u countered my effort without enough reasons to put me right( i.e, if i was wrong). I didn't mean to insult you. Even if u were insulted by that, i think u should have called my attention.