Search found 38 matches
- Mon Jan 28, 2019 4:06 pm
- Forum: Physics
- Topic: BdPhO Regional (Dhaka-South) Secondary 2019/3
- Replies: 1
- Views: 2331
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 $f$.
- Mon Jan 28, 2019 4:02 pm
- Forum: Physics
- Topic: BdPhO Regional (Dhaka-South) Secondary 2019/2
- Replies: 1
- Views: 2400
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 ...
- Mon Jan 28, 2019 3:52 pm
- Forum: Physics
- Topic: BdPhO Regional (Dhaka-South) Secondary 2019/1
- Replies: 1
- Views: 12858
BdPhO Regional (Dhaka-South) Secondary 2019/1
What will be the reading on the voltmeter? (See the figure)
চিত্রে ভোল্টমিটারে পাঠ কত দেখাবে?
- Sun Jan 20, 2019 8:04 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BDMO National Primary 2018/4
- Replies: 4
- Views: 3368
Re: BDMO National Primary 2018/4
Isn't the answer= $7:16$?
- Sun Jan 20, 2019 8:01 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BDMO National Primary 2018/4
- Replies: 4
- Views: 3368
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...
- Sun Jan 20, 2019 3:14 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Secondary/Higher Secondary 2018/3
- Replies: 2
- Views: 2744
- Sat Jan 19, 2019 8:21 pm
- Forum: Secondary Level
- Topic: Devide by $6$
- Replies: 8
- Views: 8175
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 $4$ .
$S_{n^{2}}=\dfrac {n\left( n+1\right) \left( 2n+1\right) }{6}$
So, $S_{2019^{2}}=\dfrac {2019\times 2020\times 4025}{6}$
$\Rightarrow S_{2019^{2}}=2735913250$
Now, we can easily find the remainder $4$ .
- Sat Jan 19, 2019 4:53 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Secondary/Higher Secondary 2018/1
- Replies: 4
- Views: 3526
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+...