Question

The maximum tension a rope can with stand is 60kgwt. The ratio of maximum accelerations with which two boys of masses 20kg and 30kg can climb up the rope is,

• A. 1 : 2
• B. 2 : 1
• C. 2 : 3
• D. 3 : 2

Answer 1

The correct option is B 2 : 1

$\text{Here we are considering,}$

$m_1=20kg,T=60kg\omega t$

$m_2=30kg,$

$=(60\times 9.8)N$

$=588N[\because 1kgwt=9.8N]$

Now, for $m_1$ $=20Kg$ ,

we know that,

$T-m_{1}g=m_1{a}_1$

after putting the value af $T,m_1,g$ we will get,

$588-(20\times 9.8)=20\cdot a_1$

$\Rightarrow a_1=\frac{588-196}{20}=19\cdot 6$

$\left(1\right)$

Again similarly, for $m_2=30kg$.

we can write,

$T-m_{2}g=m_2{a}_2$

After putting the values af $T,m,$ and $g$ we will get,

$588-(30\times 9.8)=30.a_2$

$\Rightarrow a_2=\frac{588-294}{30}=9\cdot 8$

$\left(2\right)$

Now,

$a_1:a_2=19\cdot 6:9\cdot 8$

$=2:1.\text{(Ans)}$