Physics, Chemistry and Biology: Post your doubts here!

[Cheryl Devane]

Can someone please explain this?

 

[Emmris]

Can someone please explain this?

I'm not dat sure but I think dat the 1st one is b) because:
- As the speed of the elevator is increased , it will take less time to do the work n according 2 the formula, work done = force * distance. Here, the force is the K.E of the elevator as its speed is increased, the K.E is also increased n the distance remains the same in the direction of the force. If we multiply the increased K.E with the same distance, the work done will increase.
- power is work done / time. When the speed is increased, it will take less time for the work to be done. So, if we divide the increased work done with the less time taken, the useful energy output ( power) will increased.

 

[Emmris]

Can someone please explain this?

I think day the second one is c) because:
- the information given say dat the depth is the same everywhere . So the potential energy ( force) of the water will be the same everywhere.

 

[Emmris]

Can someone please explain this?

According 2 me, the 3 rd one is a) because:
- at equilibrium, the sum of acw moment = sum of cw moment. I' m using the formula : moment= force* distance. The moment of the 40N should be equal to the moment of the baby . The distance from the pivot to the 40N is smaller compared to the baby . So, to produce the same moment, the weight of the baby must be less than 40N as the distance is longer. If the baby's weight would be greater than 40N then when we would multiply the longer distance with the greater weight, we will get a larger moment.

 

[Emmris]

Guys plz comment n see if the answers are correct cuz I' m not dat sure....

 

[Mohammed alomary]

This is the may June 2017 I guess ? Can the person who send it please send the full paper 2 with all the 40 questions

 

[Mohammed alomary]

But I think the first one is D and the third one is A ... not sure about the 2nd one but i think it's C

 

[Emmris]

Can u xplain why please

 

[Mohammed alomary]

For the first one as the only the speed is altered the work done is not related to the speed since work is force multiplied by distance and so distance remains as before so work is unchanged but power is force multiple by speed and as speed is more power output is also more

 

[Mohammed alomary]

And for last question ... as object is in equilibrium moments are equal and cancel each other out so if distance from baby to pivot is more the that from pivot to load then the weight should be less than 40 to cancel it out

 

[Mohammed alomary]

But the 2nd one I don't get it could be C since only the area is different and force is same but that would mean that B can also be correct since is area in X is more than that of Y and force is same in both then pressure on X from equation of pressure =force÷area is less than that of Y so it's either B or C

 

[Emmris]

I think dat ur right abt the first one....

 

[Emmris]

I just confused energy with force... silly me ...

 

[Cheryl Devane]

Thank you so much guys! It is the 2016 Specimen paper 11

 

[princess of cricket]

do any of u have hand written notes on chap inheritance <biology>

 

[Emmris]

do any of u have hand written notes on chap inheritance <biology>

Sorry no

 

[princess of cricket]

its ok i got them from the internet

 

[princess of cricket]

do we need a scientific calculator in biology paper

 

[princess of cricket]

Sorry no

do we need a scientific calculator in biology paper

 

[Emmris]

do we need a scientific calculator in biology paper

I'm not sure .... I will confirm it n will tell u ...