₦airaland Forum

mathefaro:
one thing I know for sure is that P.E increases with height while K.E increases with velocity. However, The cone with unstable equilibrium has a high potential(stored energy waiting to be released) to move farther from it's initial position when released/tilted/displaced

so u are implying ans shud be B. Increased??

A cone in unstable equilibrium has it's potential energy A. Decreased B. Increased C. Unchanged D. Oscillating
my textbuk and d jamb past questns answer contradicts each other.
Textbuk ans-A. Decreased.....reason is: potential energy decreases as the height decreases
jamb past questn ans- B. Increases....reason is: The height of the centre of gravity of a body in unstable equilibrium is usually raised. Hence P.E increases.
Pls which is the right ans?

proyeise:
A circle of perimeter 28cm is opened to form a square.What is the maximum possible area of the square?

49cm²

1. She is short as .......
a. He
b. Him
2. Let you and ..... Do it
a. Me
b. I
3. They are stronger than........
a. We
b. Us
4. It was .....who did it
a. He
b. Him
5. We supposed it was........
a. He
b. him
6. He is as tall as......
a. me
b. I

Thewhizzkid1:
Proyeise please keep posting English questions...It's very gud of u...I'll advice u all preparing for jamb to read Invisible Teacher by Dele Ashede for ur English...This book is very rich in content and it helped me a lot for my jamb..

i av A-Z (it's rich as well) by Dele Ashade also. Are both same? If no, which is better?

proyeise:
No sooner had we finished the work _____ it started to rain.
a.when
b.than
c.as
d.that

B. Than

proyeise:
Tayo is taller than ______
a.I
b.me
c.both
d.she

Tayo is taller than I (am)
so A is the ryt option

proyeise:
Find the sum of the exponential series 96 + 24 + 6 . . .
a. 144
b. 128
c. 72
d. 64.

B. 128

proyeise:
Evaluate log 8 base 0.25
a.3/2
b.2/3
c.-2/3
d.-3/2

D. -3/2

Halpher:
They are still propably on thesame parallel just dat Pcl5 is of more stable compound cos phosphor which is group 5 element has and oxidation num of +3 and +5 and that +5 is kinda stable for them.
So pcl3 is more preferable.

i mean is pcl5 amphoteric too?

Kealmin:
1. There are basic particles from which matter could b form except
a molecule
b atom
c ion
d salt

2. atom is the.......
A smallest part of a substance dat can take part in chemical reaction.
B smallest part a compound that can take part in a chemical change
C smallest part of an element which can take part in a chemical change
D smallest part of a lattice which can take part in a chemical change

3.atomicity of ozone is
A 1
B 2
C 3
D 4

4.a molecule is d smallest particle of....
A a matter that can exist in free state
B an element which can exist in free state
C a radical that can exist in free state
D a lattice that can exist in free state

5. 3NH is
3
A three moles of ammonium
B three moles of ammonia
C six moles of ammonia
D six moles of ammonium

6. the relative atomic mass of calcium is 40 this means
A the mass of calcium is 40
Bthe calcium is 40 times heavier than that of 1 atom of hydrogen
C.calcium is 40times that of 1g of hydrogen
Dcalcium is related to hydrogen through digit


7. modern standard element with which chemist define relative atomic mass is
a 12C
b 13C
c 14C
d 3H


8.the relative molecular mass of lead || trioxinitrateV is(Pb=108, N=14, O=16)
a 170
b 222
c 232
d 132


9.which one is heavier
a pbd4
bH2
cpb(NO3)2
d none of d above


10.the percentage of oxygen on sulphur|V oxide is
a 5%
b 50%
c 500%
d 25%

11.the empirical formula of C6H6 is
A CH
B C3H3
C C6H6
D 3CH
12.if d relative molecular mass of CH20 is 60 calculate it empirical formular(C=12 H=1 O=16)
A 4
B 1
C 2
D 3


13.a molecule of neon is
A ionic
B monatomic
C diatomic
D triatomic

1. D
2. A
3. C
4. A
5. B
6. C
7. A
8. C
9. B
10. B
11. A
12. C
13. B

Halpher:
It is A.

what of pcl5?

Halpher:
u tried

wich is it den?

Halpher:
Pcl3 is an example of?
A)amphoteric
B)neutral
C)basic
D)acid
E)none
In nature.

C. Basic

Halpher:
Kcl is found as an Ore in..?

ore of kCl shud be mineral sylvite or potash

proyeise:
The latent heat of fusion of ice is 80cal/g.How much heat is required to change 10g of ice at 0 degree celcius into water,at the same temperature?pls i nid d workings.

H=ml where m=10g l=80cal/g
H=10 X 80 =800cal.

proyeise:
What are the differences between electrochemical cell and electrolytic cell?

electrochemical cell-
a. It converts chemical energy into electrical energy
b.it's spontaneous in reaction
c.anode-negative electrode
d.cathode-positive electrode
electrolytic cell-
a. It converts electrical into chemical energy
b.it's non-spontaneous in reaction
c.anode-positive electrode
d.cathode-negative electrode

proyeise:
What Is The Dimension For E.M.F?

dimension should be ML²T^-3I^-1

ML²T^-3I^-1

N[sup]2

N^NN2

proyeise:
Two forces whose resultant is 100N,are at right angle to each other.If one of them makes an angle of 30 degree with the resultant,determine its magnitude.

magnitude shud be 86.6N

tuwayz:
Get comPrehensive test den

sure! Tanx

Halpher:
Have these pEepz!
The discrete particle responsible for a chemical reaction is.?
A)proton
B)neutron
C)electron
D)Nuclear charge.

C. Electron

tuwayz:
I think combining text books is the best way because all text omit some certain things others have buT for calculations I think essential and comprehensive physics texts are better

av essential nd new skul already jux wanna get one or two more

Benjaminbest:
go get principles of physics

how is it like and who is d author?

tuwayz:
plS my peeps practice formulas very well in physics and don't just rely on the given formulas but try to substitute and derive new formulas memorise the formulas well, when u see a question thAt require cAlculation don't rush in selecting a formula for d question list out the given values 1st so u can see them clearly and understand which formula you should use, thank you all

who knows a vry gud physics textbuk...esp d one dat contains transistor(well detailed)

Benjaminbest:
If a force P of 40N act in d direction due east and another force Q of 30N acts in the direction due North, calculate the resultant of these two force

Resultant should be 50N

Benjaminbest:
questions dat u are likely to see from chapter one and two
1. scientist approach to discoveries follows d order which include......
A further experiment and problem solving
b theory, negative and positive result
c experiment,hypothesis and result
d observation,hypothesis and experiment

2. which of these require crystallization most
a drug making
b cement making
c paint making
d perfume making

3. one of these is not a chemical change
a rusting
b sublimation
c slaking of quicklime
d fermentation

4. Method adopted in seperating lead || chloride from water is
a sieving
b decantation
c crystallization
d distillation

5. fractional crystallization is a method of seperating
a crude oil
b liquid_liquid mixture
c coal
d Solid of different solubilities in a liquid

6. all except one is a popular criteria for purity
a melting
b dielectric constant
c temperature
d centrifugation

7. d addition of water to calcium oxide leads to
a a physical change
b a chemical change
c the formation of a mixture
d an endothermic change

8. a chemical reaction is always associated with
a an increase in composition of one of d sub
b a change in volume of d reactant
c a change in nature of reactant
d the formation of new substance

1. D
2. A
3. B
4. C
5. D
6. C
7. B
8. D

on how it was gotten...
Distance(s)=t(u+v)/2....
But average speed=distance/time
therefore A.v =t(u+v)/t x 2
of coz u knw t wil cancel out t
A.V = (u+v)/2
hope it's clear now

smartdave1:
ya! Its true... But, pls make me understand how you got the formula, since there is no '2' in the question.
Thanks

two formulas for finding average speed.
1. A.v=distance/time
2. A.v=(u+v)/2
both would give u same answer but if distance and time were given in the questn it is adviceable u use the ist one but if only initial and final velocty were given u should go for the 2nd formula.... Coz of time factor!....so it depends on the questn.

smartdave1:
Good morning roomie... Sir Benjaminbest, Sir mathefaro and/or any one in the hux pls help me solve these physics questions:



The sped of a bus increases uniformly from 15m/s to 60m/s in 20 seconds. Calculate:
(a) the average speed
(b) the acceleration
(c) the distance travelled during the entire period.

*abstracted from New School Physics textbook*

Many thanks!

permit me to find acceleration ist
v=u+at, v=60m/s u=15m/s a=? t=20sec
60=15+20a, 45=20a, a=2.25m/s^2
c. Distance travelled: S= Ut+1/2at^2
S=15 X20 + 1/2 X 2.25 X (20)^2
S=300+450
S=750m....daz distance travelled
a. The average speed =distance/time taken
A.v=750/20
A.V=37.5m/s