physics and chemistry doubts!!

[Faiza Anwar]

What variable of a circuit does current affect? (Voltage controls brightness.. current? )

brighteness is directly proportional to voltage..

 

[Phoenix Blood]

in your first question.. it is written that 5V moves the wave 1 cm upwards.. nd the wave is moving 1.5cm upwards so we will multiply 1.5 with 5.. the answers is 7.5..
in the second part.. i ms moves the 1cm horizontally.. i cycle travels 4cm so it takes 1 x 4= 4ms.. and from this u get the frequency
tell me if the answers are correct or no..

the ray bends towards the normal as it enters the glass.. nd then away from normal as it enters air

Jazakillah

 

[Phoenix Blood]

brighteness is directly proportional to voltage..

Anything proportional to current?

 

[Faiza Anwar]

Jazakillah

your welcome..

 

[Faiza Anwar]

when an heavy and a light object are thrown at the same time why don't the heavy object's speed increase????????

 

[Faiza Anwar]

View attachment 43000

No 'C' ? Air giving k.e and all....?

the ans is D coz after evaporation the temp. of remaining liquid decreases...

 

[gary221]

Anything proportional to current?

Power/ heat losses in the cables are directly proportional to current.

 

[gary221]

when an heavy and a light object are thrown at the same time why don't the heavy object's speed increase????????

Are you talking about air resistance here?

 

[Phoenix Blood]

when an heavy and a light object are thrown at the same time why don't the heavy object's speed increase????????

Acceleration of free-fall is constant. Speed DOES increase. And, if a heavy object and a light object are both thrown together, both will fall with same acc., IF ONLY AIR RESISTANCE IS IGNORED. Air resistance is greater- greater the object is, and hence can slow down motion/speed/acc. of a body.

 

[Faiza Anwar]

Are you talking about air resistance here?

in question they say falling from table but don't mention air resistance so how comme we know that its vacuum or air??

 

[Faiza Anwar]

Acceleration of free-fall is constant. Speed DOES increase. And, if a heavy object and a light object are both thrown together, both will fall with same acc., IF ONLY AIR RESISTANCE IS IGNORED. Air resistance is greater- greater the object is, and hence can slow down motion/speed/acc. of a body.

thankyou.. that means i should chose both fall at same time...

 

[Faiza Anwar]

View attachment 42992

can u plzz tell me which paper's Question is this?? i'll solve it !!

 

[gary221]

View attachment 42992

The value for the speed of sound in air is 15oo m/s??

 

[Faiza Anwar]

The value for the speed of sound in air is 15oo m/s??

No!

 

[gary221]

No!

Wow, well.... that's what's written there...I think.

 

[Faiza Anwar]

Wow, well.... that's what's written there...I think.

which paper is this Question from??

 

[gary221]

which paper is this Question from??

I really dont know... I was just confused at the value... *shrug*

 

[Faiza Anwar]

Can some one give me some briefing on centripetal force, i get really confused with it...

 

[Hello090078601]

How do I draw the vector diagram for MAY JUNE 2013 QUESTION 3B?

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_s13_qp_33.pdf

 

[Phoenix Blood]

Can some one give me some briefing on centripetal force, i get really confused with it...

An adjective to a force--- meaning the force that draws the moving body towards the center. Like -circular motion is maintained due to the fact that there is a force in the midde that is drawing it in.