₦airaland Forum

Diction7:
[b]Young man thanks for your answers but if you're Christian then you should be ashamed of making such ungodly comments. What do you "if your game is tight" Be ashamed of thinking, saying or doing such things (Sirach 41:14). Go read Sirach 9:1-9 on "advice about women." read also Proverbs chapter 2,3,4,5,6,7. Do not invite calamity & generational disaster on yourself because of a brief ungodly & premarital/extramarital sexual pleasure. God's Word is immutable and HE IS ALIVE & IN HEAVEN. Repent from such immoral thought & speech patterns, and if you've fornicated confess & renounce your old ways. Seek the mercy of God and don't give the devil the opportunity to steal you to Hell because of a fleeting pleasure. Your destiny is much more important & great than having see... Think & pray about this. May Our Lady of Perpetual help intercede for you.[b]

MrHistorian:
They hurriedly did everything, everyone(about 5) yet uncleared that I know got cleared.

At this point, if you are still uncleared, Mountain of Fire should be your destination.

I kuku know say them don clear you.
You na boss.

ChiomaMee:
I've not been cleared oo

Did you re-upload??

No, I did not.
you will soon be cleared since the VC said it's gonna end tomorrow.

adesekosam:
actually i dont know what is worrying u.i. They are not organized at all. Up till now my porral is not yet activated for payment. Imagine, they've not even cleared some people. Is that not madness..

They don finally release me..

adesekosam:

Bro, it is not funny anymore oh.

ChiomaMee:
samuelizz ....have you been cleared

At all
if care is not taken, I will clear myself
Radarada..

What about you?

Modified ; I've been cleared

...it is not funny anymore.

Nltaliban:
I sent it



I'm too lazy to upload things on nairaland

make I no cast you sha

Aceed:
oh oh oh, you didn't put the division sign in the first line of the bolded which confused me.


Its clear now

samuelizz how did you also eliminate the D and introduce d?

I just used that for convenience

Aceed:
Boss you lost me here ooo, how did you eliminate the v or v²?

I factorized the v and it got canceled by the lower one

fashmann:
UI should start allocating halls and matric Number to those cleared last week..
Make dem do fast nah..

To those uncleared, God is your strength
I know how it feels like..

Clearance should continue this week.

See this one

Damayogenius18:
The coefficient of volume of expansion of glycerine is 49 x 10 ^-5 K^-1....what is the fractional change in its density for a 30^•¢ rise in temperature...A..10...B 15...C..12..D..20

density (d) = mass/volume(v)

but the mass is constant.

d × v = K.

d × v = D × V.

the lower case letters represent the initial substance
the upper case letters represent the final substance.

V = dv/D

but we know that..

cubic expansivity (¥) = (V - v)/v∆T.

sub..

¥ = (dv/D - v)v∆T

¥ = (d/D - 1)/∆T.

¥ = (d - D)/D∆T.

(d - D)/D = ¥∆T.

∆d/d = (49 × 10^-5 × 30)

∆d/d = 0.0147

sirgalahad26:
thank god i have a boss

Boss bawo?
na your steps I dey follow oh

Ajet001:
Very difficult to believe.


Baba we don leave your 419 page ooo.

sirgalahad26:
the way i dey reason you ehn... you go like food!

I like food pass my gf

Nltaliban:
They know it's your favourite page

Nltaliban:
Don't mind him oo.. Mellanby is a very good hall. Hall for fine boys. In fact, historian likes the hall

Maybe he's referring to the hall as a dungeon because it's old.




Your Hall doesn't matter, it won't determine your cgpa bro, let's stop disturbing ourselves over small things like hall. We have beautiful days ahead

The Hall food ehn

This page sounds funny.
page 419

Ajet001:
Well, there's no much to say
You already know what to do, you're already aware of the Exam format.

Keep studying hard and smart and start learning to solve questions that involves calculations without using a calculator.

Learn how to be calm and answer questions with the least time consuming method.

You guys here are doing great as early preparations is a big boost, do not relent and keep studying.


You'll laugh at last by His grace.



Oga Samuelizz dem don give you hall and mat no?

When they never clear me sef

sirgalahad26:
not cleared yet talkless of getting H.O.R.

The Lord is our Strength

*PROJECTILES.*

I'm sure we are all familiar with the topic projectile.. But let's assume you don't know, now , what is projectile ?


Well, *projectile is the launching of a body into space which is under the influence of gravity.*

From that definition, it can be said that , when dealing with the topic projectile, we are going to be dealing with *g* (acceleration due to gravity) a lot.

Projectile is a 2 - dimensional motion, that is , it consists of the x , y components... Are you confused??... Just be calm, you will understand soon.

The x components is always the horizontal components , in a better understanding, the component parallel to the ground while the y components is always the vertical component i.e it is always perpendicular to the ground. ...


y.
| /
| /
| /
| /
|/___________y

Now, you have an idea of what I've been saying.

Let's say a body was projected with a velocity *U* and it makes an angle *B* with the horizontal.

When you resolve the velocity into the vertical and horizontal components using your trigonometry knowledge.

You will have .

Ux = UcosB (Ux is the horizontal component)

Uy = UsinB (Uy is the vertical component)

Right?.. Good, now let's proceed.

*TERMS USED IN PROJECTILE*

In every topic in physics, there are always some terms always used in the topics, well, projectile is not an exception!

1. *MAXIMUM HEIGHT* : From the word "maximum" and the word "height" I'm sure you are getting the definition already..

It can be defined as the *maximum vertical distance* which a body attains from the *point of projection*

Simple, right?

You should know that at maximum height, final velocity V is always zero because the body that was projected will stop momentarily before coming down!!

Let's now derive the formula for maximum height..

From our popular formula of motion, one of them is

v² = u² ± 2gh.
But since the body is projected upwards, that makes our *g* to be negative.

v² = u² - 2gh.

We also know that, when a body is projected upwards, and since the height is a vertical distance, it will be affected by *g*, only the horizontal distance is not affected by *g*, we will get to that.

We know that Uy = UsinB. And that max height Vy = 0

0² = (UsinB)² - 2gh

2gh = u²sin²B

h = u²sin²B/2g.

And that's the formula for maximum height.

2) *TIME OF FLIGHT*: It is the time required for the body to reach the same level of point of projection i.e the time taken for the journey.

In our motion formula, we have,

h = ut - ½gt²

At the end of the journey, the body will touch the ground again right?, do you agree with me?.. Good

If it touched the ground again, the vertical height with be 0 right?... Agreed?

Since we are making use of vertical motion, Uy = UsinB

0 = UsinB•t - ½gt²

UsinB = ½gt

t = 2usinB/g

And that is our time of flight.

NB : Time of flight is always twice the time it took to reach the maximum height.

3) *RANGE*: Range can be defined as the *maximum horizontal distance* from the point of projection in which the body projected touch the line of point at the *same horizontal level*

Please, it must always be at the *same level at which it was projected from*

Now let's derive the formula, we are still talking of projectile here..

From one of our motion formula.

We have ,

h = Uy•t - ½gt²

But since Range is represented with R.

And since it is an horizontal motion, g = 0, we substitute Uy as Ux

R = Ux•t - ½(0)t²

R = Ux•t

Where t is our time of flight, t = 2usinB/g and Ux = ucosB.

R= ucosB × 2usinB/g

R = 2u²sinBcosB/g

But 2sinBcosB = sin2B

R = u²sin2B/g

And that is our formula for Range..

Now, let me clarify something..
In a question , you might be asked for the horizontal distance covered and in another question, you will be asked for range.

Please , note that Horizontal distance is deferent from Range.

When it comes to Range, the body must always be at the *same level* with the point the body was projected..

But when it comes to *horizontal distance*, it not necessary that the body must be at the same level with the point at which the body was projected..

The formula for horizontal distance is R = Ux•t. I.e horizontal component of the velocity × the total time.

Lets take an example, let's say a body was projected upwards from the *top of a building* and it hits the *ground after some time. From that, you can see that the ball did not land at the same level with the point at which the body was projected...

So, they are different!!.

Damayogenius18:
...thanks boss..are you a medical student or engineering?

Let's just say engineering.

Gracy3535:
i cant find lamlad here. Pls is New school ok. Cus i dnt want to waste another money like that of essential

New school is okay too.
solve a lot of past questions

Damayogenius18:
OK boss...y is vx now 10...are we also ask to calculate resultant velocity...the answer that was chosen is 30m/s..maybe I don't understand the question sha!

(Vx)² = (Ux)² + 2gh.

but g is always zero when it comes to horizontal components

(Vx)² = (Ux)² + 2(0)h

(Vx)² = (Ux)²

Vx = Ux.

Gracy3535:
Thanx boss for the working. I actually did cross multiplcation to get 30m/s

LOL.
you're welcome.

Damayogenius18:
....boss u lost me o..I know resultant velocity v= √(vx^2 + vy^2)..do we need to calculate Vy again...I think it has been given as 30m/s..I think they ask the horizontal velocity the ball hits the ground not the resultant..

Vy is 30ms-¹ when it was thrown vertically downwards.

The new Vy I solved for was when it was thrown horizontally.

Damayogenius18:
...I don't get what u r implying boss...one aspect is about surface tension which I try to point out to you that it has formula..the other aspect is Tension which I said it also has multiple formula based on the topic...in sound,there is tension formula e.g string..f= √TL/ M..we can make T subject of formula to get tension...in uptrust, tension T= mg- pvg...in circular motion..T=mv^ 2/ r + mg... In a lift..T= m(a+g)...so on...so I don't understand what you are trying to say..

I never said surface tension has no formula, I was talking about "tension" which has no particular formula.

Damayogenius18:
7. A physics student standing on the edge of a cliff throws a stone vertically downward with an
initial speed of 10.0 m/s. The instant before the stone hits the ground below, it is traveling at
a speed of 30.0 m/s. If the physics student were to throw the rock horizontally outward from
the cliff instead, with the same initial speed of 10.0 m/s, what is the magnitude of the velocity
of the stone just before it hits the ground...A..10..B..20..C..30..D..40

Vy = final velocity of the vertical component of the velocity.

Uy = initial velocity of the vertical component

Ux = initial velocity of the horizontal component

Vx = final velocity of the horizontal component

when the body was thrown vertically downwards

(Vy)² = (Uy)² + 2gh.

30² = 10² + 2(10)h

20h = 800

h = 40m ( the height of the building )

Now, when the ball was thrown horizontally..

(Vy)² = (Uy)² + 2gh.

but Uy = 0 , since the ball was thrown horizontally.

(Vy)² = 2(10)(40)

(Vy)² = 800

Vy = √(800)ms-¹ (that is the final vertical component of the velocity )

But Ux = Vx (horizontal component is not affected by g)

The velocity it hits the ground V = √[(Vy)² + (Vx)²]

V = √[(√800)² + (10)²]

V = √(800 + 100)

V = √(900)

V = 30ms-¹

Eben331:
how can tension be derived in mechanics? Which physics textbook do u use? I am sorry for asking too much questions. Thanks.

You can use lamlad, it is a very good text.

Damayogenius18:
...doc,there is formula for surface tension....is force per unit length acting on the surface of the liquid....F/l...MLT^-2/L...MT^-2.... Force can be generally group into pull or push...tension, thrust...e.t.c are forces..Tension has many formula depending on the question but let's use this...T= mv^2/ r + mg..T=ma + mg...MLT^-2 + MLT^-2...T =MLT^-2....

Did you read what you quoted?

Eben331:
Thanks bro, pls write d formula for both surface tension and tension out.

surface tension = Force/length.

Tension has no particular formula.
it is always derived when solving questions especially in mechanics

Eben331:
bro, pls write the formula for angular velocity when it is measured in rev/s.

It doesn't really have a particular formula tho.

it is advisable that when solving for angular velocity, the unit should always be in rad/s.

just know that 1rev/s equals 2πrad/s