Lv 42,643 points

# Yuki

• ### phy energy level

can photon have inelastic collision with an atom?

thanks

1 個解答其他 - 科學5 年前
• ### atomic physics

1. is (1) the correct option?

2. please explain why each option can/ cannot increase the number?

3. why is it B but not C?

thanks!

1 個解答其他 - 科學6 年前
• ### maths probability

可唔可以解釋下條式係點諗出黎?

thanks

1 個解答數學6 年前
• ### phy E&M

https://i.na.cx/N209O5.jpg

https://i.na.cx/1x62yi.jpg

1. Why are (2), (3) correct?

https://i.na.cx/E8N07i.jpg

https://i.na.cx/5iw9Ce.jpg

https://i.na.cx/890F5n.jpg

2. part c: is the answer wrong? Direction of magnetic force should be horizontally right, not up the plane?

https://i.na.cx/mZm85s.jpg

3. part a: should it be clockwise or anticlockwise?

https://i.na.cx/5doNLx.jpg

4. why are 1,3 correct but not 2,4?

https://i.na.cx/kfpc35.jpg

5. why are 5,6 incorrect?

https://i.na.cx/G6cyvq.jpg

https://i.na.cx/7r6684.jpg

6. How do I kw whether it is E/V which changes when the plates are moved apart?

thanks

1 個解答其他 - 科學6 年前
• ### electric shock

in each of the above cases, would the person receive electric shock if he puts his finger at the place indicated by the arrow? are there any criteria for electric shock to occur? thanks!

1 個解答其他 - 科學6 年前
• ### phy electricity

1. why is (1) incorrect?

2. why is (2) correct?

3. why are copper wires insulated?

4. doesnt V depend on the width of the gap?

5. is (3) correct? since the particle is released from rest, it should follow the electric filed line?

Thanks!!

1 個解答其他 - 科學6 年前
• ### bio mc

1. less blood flows to blood capillaries when the weather is cold? why is it not involved in temperature regulation?

2. why is it D? can line transect be used to measure the abundance?

3. could you please explain why is B correct while others are wrong?

4. why is active transport not involved in A?

5. why not C?

1 個解答生物學6 年前
• ### phy magnetism

why is it C?

why is it D?

http://postimg.org/image/ej9vfzlr5/

why is it C but not A?

why is (2) correct?

thanks!!

1 個解答其他 - 科學6 年前
• ### magnetic induction 2

why does the loop leave the magnet at a higher speed? opposing magnetic force is acting on it?

https://i.na.cx/agE60i.jpg

http://i.na.cx/3R99br.jpg

please explain how (3) is achieved

thanks!

1 個解答其他 - 科學6 年前
• ### magnetic induction

please explain why each option can/ cannot make the bell ring continuously

why is it D but not C?

please explain why each option can/ cannot demagnetise a steel rod

why is it D?

https://i.na.cx/3Tsss2.jpg

CN is the normal of the coil with the direction determined by right hand grip rule

what does this mean? how is the direction determined? what does it represent?

thanks!

1 個解答其他 - 科學6 年前
• ### electrostatics

2. does the graph mean that electrostatic force is 0 when B is neutral?

4. b) should the EPE be negative? then (d) should also be negative then?

Thanks!!

1 個解答其他 - 科學6 年前
• ### physics problems 2

why are there no dark fringes between spectral lines?

245: why is (2) incorrect? fringe separation in diffraction grating increaseswith path difference?

http://postimg.org/image/e7zyblmxj/

shouldn't the formula include length f the wire also?

which one should be the answer? A or D? please explain both options

http://postimg.org/image/ui23pphm9/

why would the image become brighter?

Thanks

1 個解答其他 - 科學6 年前
• ### phy problems 1

http://postimg.org/image/hk7j1hbkj/

what does the word aperture mean? how is the answer obtained?

could you please explain the graph for diffraction? why are there increases in intensity beside the central one?

http://postimg.org/image/nvt396u1j/

who no diffraction takes place in part d?

why is it A?

how is sound related to density and temperature of the medium?

http://postimg.org/image/nbspqz0q7/

why would the max reading appear beside O but not at O?

Thanks

1 個解答其他 - 科學6 年前
• ### phy electromagnetism

1. why would the pointer go back to zero after deflection?

http://postimg.org/image/u9r1j78ir/

2. why isn't resistance of the coil related to induced emf?

http://postimg.org/image/iibhkump5/

http://postimg.org/image/q3dd3t8uv/

http://postimg.org/image/z2hhde6cp/

4. is there any current in the coil? isnt it true that the currents induced on 2 opposite sides of the coil cancel each other?

http://postimg.org/image/7yegmb1yh/

5. how to determine the direction of net magnetic force?

http://postimg.org/image/4phl6oo2n/

6. please describe the motion of the ring with explanation

http://postimg.org/image/d4qhij149/

thanks!

1 個解答其他 - 科學6 年前
• ### maths mc questions

1.

將-2y變左2y (as y<0) --> 兩邊除y --> ans=b?

i know im wrong but why?

2. how can i arrive at the answer?

3 個解答數學6 年前
• ### maths questions

1. http://s1353.photobucket.com/user/s031026/media/ma... you please show your steps? 2.http://s1353.photobucket.com/user/s031026/media/ma... is it B but not A? 3.http://s1353.photobucket.com/user/s031026/media/ma... 0.84My ans: [(9/10)(2/3)]^2 +2(9/10)(1/3)(9/10)(2/3) + 2(1/10)(2/3)(9/10)(2/3) = 0.8Why is my answer wrong? 4.http://s1353.photobucket.com/user/s031026/media/ma... is it A but not C? what's thedifference between these two answers? 5.http://s1353.photobucket.com/user/s031026/media/64... show your steps Million thanks!

1 個解答數學6 年前
• ### physics momentum

why can't (2) be the subsequent motion?

could you pls explain (3)?

how can i calculate theta without knowing the initial speed of the box?

4. Is it true that a person with greater weight will experience more serious injury in an impact?

2 個解答其他 - 科學6 年前
• ### dse chem questions

1. How to determine the oxidation number of carbon in organic compounds?eg. CH3COOH and CH3CH2OH

2. Do alkenes react with HCl?3. Each water molecule can form at most 4 hydrogen bonds but only 2 onaverage

Each HF molecule can form at most 4 hydrogen bonds but only 1 on averageEach NH3 molecule can form atmost 4 hydrogen bonds but only 1 on averageAre these sentences correct?4. Why does wax act as fuel in gaseous state in a burning candle but notsolid or liquid state?5. #33 Ans: D

why is (3) correct? it produces CO2 as well?

6. #84 Ans:D why are (3) and (4) correct?

Thanks so much!!!!!

1 個解答化學6 年前
• ### energy problems

1 個解答其他 - 科學6 年前