Search found 38 matches

by SINAN EXPERT
Mon Jan 28, 2019 4:06 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/3
Replies: 1
Views: 685

BdPhO Regional (Dhaka-South) Secondary 2019/3

A spring of spring constant $k$ with a mass m attached to it has a resonant frequency $f$. If the mass is doubled and the spring constant is changed to $4k$, then express the new resonant frequency $f_n$ in terms of $f$.
by SINAN EXPERT
Mon Jan 28, 2019 4:02 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/2
Replies: 1
Views: 746

BdPhO Regional (Dhaka-South) Secondary 2019/2

BdPhO Regional (Dhaka-South) Secondary 2019(2).png A solid object of mass $4 kg$ is heated at a constant rate $50 W$. The object is kept inside a thermally isolated container so that it cannot radiate heat to the environment. The temperature vs time graph is given. What is the specific latent heat ...
by SINAN EXPERT
Mon Jan 28, 2019 3:52 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/1
Replies: 1
Views: 8265

BdPhO Regional (Dhaka-South) Secondary 2019/1

BdPhO Regional (Dhaka-South) Secondary 2019(1).png
BdPhO Regional (Dhaka-South) Secondary 2019(1).png (13.87 KiB) Viewed 8244 times

What will be the reading on the voltmeter?
(See the figure)

চিত্রে ভোল্টমিটারে পাঠ কত দেখাবে?
by SINAN EXPERT
Sun Jan 20, 2019 8:04 pm
Forum: National Math Olympiad (BdMO)
Topic: BDMO National Primary 2018/4
Replies: 4
Views: 1014

Re: BDMO National Primary 2018/4

samiul_samin wrote:
Thu Jan 10, 2019 9:53 am
Answer
$7:32$
Isn't the answer= $7:16$?
by SINAN EXPERT
Sun Jan 20, 2019 8:01 pm
Forum: National Math Olympiad (BdMO)
Topic: BDMO National Primary 2018/4
Replies: 4
Views: 1014

Re: BDMO National Primary 2018/4

At first let's make the picture easy. BDMO National Primary 2018(4).png Here, $AB=BC=CE=EA=a$ and $FE=b,$ $ED=c$ So, $AE=AF+FE=3FE+FE=4FE=4b=a$ Now, $a=4b$ and similarly $a=4c$ Hence, $4b=4c$ $⇒b=c$ The areas of yellow coloured triangles $=\dfrac {1}{2}\times BC\times CD+\dfrac {1}{2}\times EF\time...
by SINAN EXPERT
Sun Jan 20, 2019 3:14 pm
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Secondary/Higher Secondary 2018/3
Replies: 2
Views: 932

Re: BdMO National Secondary/Higher Secondary 2018/3

Answer:
$M_{144}$
$=6*6*4*1$ $(S=17)$
$=4*3*4*3$ $(S=14)$
$=6*2*4*3$ $(S=15)$
$=6*6*2*2$ $(S=16)$
by SINAN EXPERT
Sat Jan 19, 2019 8:21 pm
Forum: Secondary Level
Topic: Devide by $6$
Replies: 8
Views: 3869

Re: Devide by $6$

$****VETO****$
$S_{n^{2}}=\dfrac {n\left( n+1\right) \left( 2n+1\right) }{6}$
So, $S_{2019^{2}}=\dfrac {2019\times 2020\times 4025}{6}$
$\Rightarrow S_{2019^{2}}=2735913250$
Now, we can easily find the remainder $4$ :?:.
by SINAN EXPERT
Sat Jan 19, 2019 4:53 pm
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Secondary/Higher Secondary 2018/1
Replies: 4
Views: 1243

Re: BdMO National Secondary/Higher Secondary 2018/1

Here is the easier way to solve the problem. শর্তমতে, $x^{2}\left( 2-x\right) ^{2}=1+2\left( 1-x\right) ^{2}$ বা, $x^{2}\left( x-2\right) ^{2}=1+2\left( x-1\right) ^{2}$ বা, $\left\{ x\left( x-2\right) \right\} ^{2}=1+2\left( x-1\right) ^{2}$ বা, $\left\{ (x-1+1)\left( x-1-1\right) \right\} ^{2}=1+...