Q&A - P4 Science

[janice_0950]

nicnac:

No.1 lens X and lens Y block out too much light.. Total darkness. Lens w makes little difference. Lens z blocks out abt 50% of light.. So it seems fair.

Dear nicnac,
thank you for your help again!!

:spank: OMG! another questions I still unsure + ...... :imdrowning: :?: :mad:

^^^screaming in alarm^^^

:thankyou:

[dioprem]

janice_0950:

hi all I have few questions that I unable to explain. Sigh! really poor in my science:(

please kindly help me ......... scream in alarm!!


(2) Real dun understand how to explain?
http://s417.photobucket.com/user/bin0950/media/4-7.jpg.html



thousand of thank you!!!

For the insecticide question, the \"cloud\" of insecticide is actually in the liquid state itself, much like the clouds in the sky. Only difference is the clouds in the sky are made up of tiny water droplets while those from the can are made up of droplets of insecticide. Since they are both liquid and of the same substance, their mass, state and volume must be the same.

[dioprem]

As for the last question Janice, i cannot really see the question clearly. Perhaps you could re-upload it with a higher resolution. Thank you.

[dioprem]

janice_0950:

hi all I have few questions that I unable to explain. Sigh! really poor in my science:(

please kindly help me ......... scream in alarm!!

(3)
http://s417.photobucket.com/user/bin0950/media/2-17.jpg.html

question (a) is Solid. Why? Can be answer Liquid? As both are cannot compressed.


thousand of thank you!!!

As for your third question, the answer can actually be liquid. There are some liquids that can be compressed though. Which is why solid may be the more correct answer. Although I would certainly think that liquid as an answer would be acceptable.

[jwxh]

can someone explain why more droplets are found on aluminium container than on clay container. both containers contain ice-water. it is on chapter HEAT.

[dioprem]

jwxh:

can someone explain why more droplets are found on aluminium container than on clay container. both containers contain ice-water. it is on chapter HEAT.

Aluminium, being a metal, is a better conductor of heat than clay is. So even though both containers contain ice, the temperature of aluminium would be lower than that of the clay since the aluminium would lose heat faster to the ice. So more water vapour would lose heat to the aluminium container and thus condense.

Hope this helps.

[janice_0950]

dear dioprem,

thank you so much!

Have a blessing & fun school holiday! ^_^

[jwxh]

plse help and explain why you choose the answer. tks


Tom is wearing a red shirt with blue horizontal stripes. When he enters a room
that is lighted by only a dim red light, his shirt appears __________

1) black
2 ) red with black stripes
3) black with blue stripes
4) red with blue stripes

[dioprem]

jwxh:

plse help and explain why you choose the answer. tks


Tom is wearing a red shirt with blue horizontal stripes. When he enters a room
that is lighted by only a dim red light, his shirt appears __________

1) black
2 ) red with black stripes
3) black with blue stripes
4) red with blue stripes

White light comprises of 3 primary colours, red, green and blue. So the reason an object appears red is because it is absorbing green and blue light while reflecting red light. Similarly an object appears blue since it only reflects blue light while absorbing red and green light.

Now the issue is Tom is in a room with only red light. Hence the red portions of the shirt will still appear red since the red light will be reflected. However the blue stripes will absorb red light. Since there is no light reflected, it will appear black. Hence the answer would be (2).

Hope this helps.

[jwxh]

tks very much.