Optimist1998:

Oh .....hopefully I won't forget again

Insecta is the most appropriate answer.

castrokiller:
forget cut off and study hard for 260 and above.

Juat the Percentage Cutoff would ne Nice please

Physics

-The resultant force of a couple is ………?
A. Infinity
B. Zero
C. One
D. Half


- Capacitors are used in the induction coil to
A. control circuits
B. prevent distortion of electric fields
C. prevent electric sparks
D. dissipate energy

- If the mechanical advantage of a machine is 4. What is its ratio for LOAD to EFFORT?
A. 4:01
B. 1:04
C. 5:01
D. 2:01

-If a projectile has maximum range of 36m, find the speed of projection (Take g = 9.8m/s 2 )
A. 27m/s 2
B. 2m/s 2
C. 4m/s 2
D. 7m/s 2

Same rule; explain your answers

---

Edit: The question in bold

Optimist1998:
Physics

The fig above shows three different ways of hanging a heavy picture from a hook. the tension in the string will be

A. Greatest in X
B. Greatest in Y
C. Greatest in Z
D. Same in each one

+A plastic sphere floats in water with 50% of its volume submerged. if it floats in glycerine with 40% of its volume submerged,the density of the glycerine is?
A. 1400 kgm-3
B. 1250 kgm-3
C. 500 kgm-3
D. 1000 kgm-3

A progressive wave is represented by
y=10Sin(1000πt−πx/34)
Two layers of the wave separated by 153cm have a phase difference of
A. 270 degrees
B. 45 degrees
C. 90 degrees
D. 180 degrees
E. No Correct Option

Still unanswered

Optimist1998:

Still unanswered

please answer now.....

Where is Donpre?? I like the guy...he is a genius.

If the mechanical advantage of a machine is 4. What is its ratio for LOAD to EFFORT? A. 4:01 B. 1:04 C. 5:01 D. 2:01 The answer is A.4.01....MA=Load/Effort.

Optimist1998:

Density
+A plastic sphere floats in water with 50% of its volume submerged. if it floats in glycerine with 40% of its volume submerged,the density of the glycerine is?

This is a question on relative density (we're comparing the densities of two things)

Given parameters.
volume submerged in water =50%
" " " glycerine =40%
Density of water =1000kgm3 (the density of water is almost never given)
Density of glycerine. =x

There are two ways of comparing densities.....
First formula: volume submerged in water/volume submerged in glycerine

Second formula: Density of glycerine/density of water

Like most things in physics, simply equate the two equations

50/40=x/1000
x=50*1000/40
x=1250kgm3
Here we have it.....option B

+I. Density of the liquid.
II. Acceleration due to gravity.
III. Type of container of the liquid.
IV. The constituents of the liquid.
which of the above conditions will NOT affect the pressure of fluid?

Pressure in fluids= Vpg
v=volume
p=density
g= g as we know it.
So III and IV will not affect pressure in fluids

Nuel25846:
If the mechanical advantage of a machine is 4. What is its ratio for LOAD to EFFORT? A. 4:01 B. 1:04 C. 5:01 D. 2:01 The answer is A.4.01....MA=Load/Effort.

Correct

Nuel25846:
Where is Donpre?? I like the guy...he is a genius.

Probably studying

castrokiller:
[color=#006600][/color]

Your answers are both correct

Optimist1998. The fig above shows three different ways of hanging a heavy picture from a hook. the tension in the string will be A. Greatest in X B. Greatest in Y C. Greatest in Z D. Same in each one.....the answer should be C.

Xup pals, I was expecting to meet questions. kinda disappointed

As for my absence, I was busying entering queues after queues unto jamb reg wahala. Still didn't do my reg

@"he is a genius" you kidding ryt?. I'm averagely intelligent jor

Nuel25846:

let's say the answer is B....as for the E when molecule of gases hit the vessel in which they are contain kinetic energy is is not conserved,the energy will convert to another form of energy.....so the typo is not in the question but the answer.

"E. The collisions of molecules with each other are inelastic"

You should pay attention to details. it clearly stated collision with each other.

The question is correct, just the "inelastic" typo

Nuel25846:
Optimist1998.
The fig above shows three different ways
of hanging a heavy picture from a hook.
the tension in the string will be A. Greatest in X
B. Greatest in Y
C. Greatest in Z
D. Same in each one.....the answer should be C.

Try to imagine this; you're holding a rope like the one below with both hands . Lets say it's tied to two tall buildings and you're stuck on top. What position would be more comfortable;
>>Hold the rope with your arms straight up or
>>Spread your arms
(piture attached)




Ps: by comfortable I mean less strain/pain on your muscles/hand

Optimist1998:
Physics

-The resultant force of a couple is ………?
A. Infinity
B. Zero
C. One
D. Half

B

- Capacitors are used in the induction coil to
A. control circuits
B. prevent distortion of electric fields
C. prevent electric sparks
D. dissipate energy

I'd go with D

- If the mechanical advantage of a machine is 4. What is its ratio for LOAD to EFFORT?
A. 4:01
B. 1:04
C. 5:01
D. 2:01
_

Most Def A

-If a projectile has maximum range of 36m, find the speed of projection (Take g = 9.8m/s 2 )
A. 27m/s 2
B. 2m/s 2
C. 4m/s 2
D. 7m/s 2

I'm assuming there isn't an angle. using the formula for range, there wasn't a correct option but using the formula for maximum height, A would be correct

Are you sure the question is correct?... and the S.I unit of the answers is also wrong

Donpre:


I'm assuming there isn't an angle. using the formula for range, there wasn't a correct option but using the formula for maximum height, A would be correct

Are you sure the question is correct?... and the S.I unit of the answers is also wrong

I didn't even notice the SI unit

As for the question, I'll let it slide as a typo......

Donpre:

"E. The collisions of molecules with each other are inelastic"

You should pay attention to details. it clearly stated collision with each other.

The question is correct, just the "inelastic" typo

I just recently discovered that the collision of molecules with each other is not perfectly elastic as some energy is transferred to the next molecule causing that molecule to move (Kinetic energy). Sadly our textbooks didn't stress this point...........

Optimist1998:

I just recently discovered that the collision of molecules with each other is not perfectly elastic as some energy is transferred to the next molecule causing that molecule to move (Kinetic energy). Sadly our textbooks didn't stress this point...........

ermmm... I thought all molecules in gaseous state are already in continual motion due to kinetic energy already acquired

it could be plausible that molecules that collided with the container lose their kinetic energy and have to regain it from another molecule

Donpre:

ermmm... I thought all molecules in gaseous state are already in continual motion due to kinetic energy already acquired.

you can have a perfectly elastic collision in gaseous molecules when
-all molecules posses the same amount of energy individually or discretely so nothing increases or decreases in terms of energy.


This is not always the case as the energy of these molecules are affected by external factors. Due to these factors, some molecules possess somewhat higher amount of energy ( although very negligible) when compared to others. When they collide kinetic energy may decrease or increase.

Somehow I feel the Kinetic theory has more to do with 'ideal gas' in other words "noble gases".

Optimist1998:

Try to imagine this; you're holding a rope like the one below with both hands . Lets say it's tied to two tall buildings and you're stuck on top. What position would be more comfortable;
>>Hold the rope with your arms straight up or
>>Spread your arms
(piture attached)




Ps: by comfortable I mean less strain/pain on your muscles/hand

I kinda used the parallelogram law of vector.

All these questions are so confusing....

Nuel25846:

I kinda used the parallelogram law of vector.

parallelogram law....That's even better.
I wanted to create a mental picture before applying laws. From the rope analogy, you'll definitely feel "more" pain when your arms are wide apart. Why? You're spreading your arms at an angle.

But when your arms are straight up, just your weight is pulling you down. Now this cancels out option C.

What's next? Now that we know the answer is between A and B. You can now apply any law you wish to apply to find out which case has the highest tension.


Either ways Tension would be greatest in Y...option B

Optimist1998:
parallelogram law....That's even better.
I wanted to create a mental picture before applying laws. From the rope analogy, you'll definitely feel more pain when your arms are wide apart. Why? You're spreading your arms at an angle.

But when your arms are straight up, just your weight is pulling you down. Now this cancels out option C.

What's next? Now that we know the answer is between A and B. You can now apply any law you wish to apply to find out which case has the highest tension.


Either ways Tension would be greatest in Y...option B

Yeah, true.....pls more questions.

Nuel25846:

Yeah, true.....pls more questions.

Ok, but that'll be later I'm a bit busy now.

mainwhile

Pressue
In the fig above if the atmospheric pressure is 760mm, the pressure of the chamber G is
A. 660mm
B. 690mm
C. 830mm
D. 860mm

Tension
A 1000kg elevator is descending vertically with an acceleration of 1.0ms -2 , if the acceleration due to gravity is 10ms -2 , the tension in the suspending cable is
A. 1.0N
B. 10.0N
C. 9000.0N
D. 11 000N

Still Pressure
A rectangular tank contains water to a depth of 2m, if the base is 4m x 3m, calculate the force on the base (Density of water = 10 3 kgm -3 , g = 10ms -2 )
A. 1.4 x 10 2 N
B. 24 x 10 4 N
C. 2.0 x 10 4 N
D. 1.7 x 10 3 N

Which of the following is true of sounds?
A. sound travels faster in air at 20 o C than at 30 o C
B. the frequency of a given sound wave changes when it crosses the boundary seperating two media
C. the wavelength of a given sound wave in air decreases as the temperature increases
D. sound waves cannot be reflected

Please lets discuss this......
Why is C the answer, I don't agree with any of the options above. Maybe I'm missing something.

Tension A 1000kg elevator is descending vertically with an acceleration of 1.0ms -2 , if the acceleration due to gravity is 10ms -2 , the tension in the suspending cable is A. 1.0N B. 10.0N C. 9000.0N D. 11 000N 1000kg*1.0ms+1000kg*10ms=11000N ans D

Optimist1998:
Which of the following is true of sounds?
A. sound travels faster in air at 20 o C than at 30 o C
B. the frequency of a given sound wave changes when it crosses the boundary seperating two media
C. the wavelength of a given sound wave in air decreases as the temperature increases
D. sound waves cannot be reflected

Please lets discuss this......
Why is C the answer, I don't agree with any of the options above. Maybe I'm missing something.

I think there isn't a correct option too

@Option C, Since velocity increases as temperature increases, and frequency remains constant, then wavelength should also increase and not decrease... could be a typo or a mistake. I'll Google search just to be sure

Nuel25846:
Tension A 1000kg elevator is descending vertically
with an acceleration of 1.0ms -2 , if the
acceleration due to gravity is 10ms -2 ,
the tension in the suspending cable is
A. 1.0N
B. 10.0N C. 9000.0N
D. 11 000N
1000kg*1.0ms+1000kg*10ms=11000N ans D

which formula did you use?