Answer
Verified
405k+ views
Hint: In such types of questions we calculate moments about a point and balance the clockwise and counterclockwise torques as the system is in equilibrium.
Formula used – $\sum {{M_A} = 0} $
Complete step-by-step answer:
Let the tension in the left string be ${T_1}$ and the right string be${T_2}$.
Three forces are acting on the meter stick, i.e. ${T_1}$,${T_2}$ and mg, Where the mass of the small object is m. Since the rod does not rotate so that the net torque is zero and the system is in translational balance, we have the condition that the sum of torques around any point on the stick must be zero.
We can choose any point we want to do our torque analysis, let's choose the left end of the stick because the torque ${T_1}$ will be zero.
$({T_1} \times {r_1}) - ({T_2} \times {r_2}) - ({m_1}g)({m_2}) = 0$
${m_1}$=400g=0.4kg,
${r_1}$=60cm=0.6m,
${r_2}$=1−0.6=0.4m, l=1m,
${m_2}$$\sum {{M_A} = 0} $ =100g=0.1kg
$ \Rightarrow {T_1} \times 0.6 - {T_2} \times 0.4 - 0.4 \times 0.1 \times 9.8 = 0$
$ \Rightarrow 0.6{T_1} - 0.4{T_2} = 0.392.........(i)$
The two tensions must support the total weight of the system, so we have
${T_1} + {T_2} = 0.4 \times 9.8 + 0.1 \times 9.8 = 4.9....(ii)$
Multiply eqn(ii) with 0.4 and add with eqn(i), we get
$
0.6{T_1} - 0.4{T_2} = 0.392 \\
\dfrac{{0.4{T_1} + 0.4{T_2} = 1.96}}{{ \Rightarrow {T_1} = 2.35N}} \\
$
Substitute the value of ${T_1}$in eqn (ii) we get,
$ \Rightarrow {T_2} = 2.55N$
Hence the tensions in the two strings are 2.35N and 2.55N.
Note: In such types of questions, we need to take care in selecting the point about which we calculate the next moment as such points should be selected to eliminate as many variables as possible.
Formula used – $\sum {{M_A} = 0} $
Complete step-by-step answer:
Let the tension in the left string be ${T_1}$ and the right string be${T_2}$.
Three forces are acting on the meter stick, i.e. ${T_1}$,${T_2}$ and mg, Where the mass of the small object is m. Since the rod does not rotate so that the net torque is zero and the system is in translational balance, we have the condition that the sum of torques around any point on the stick must be zero.
We can choose any point we want to do our torque analysis, let's choose the left end of the stick because the torque ${T_1}$ will be zero.
$({T_1} \times {r_1}) - ({T_2} \times {r_2}) - ({m_1}g)({m_2}) = 0$
${m_1}$=400g=0.4kg,
${r_1}$=60cm=0.6m,
${r_2}$=1−0.6=0.4m, l=1m,
${m_2}$$\sum {{M_A} = 0} $ =100g=0.1kg
$ \Rightarrow {T_1} \times 0.6 - {T_2} \times 0.4 - 0.4 \times 0.1 \times 9.8 = 0$
$ \Rightarrow 0.6{T_1} - 0.4{T_2} = 0.392.........(i)$
The two tensions must support the total weight of the system, so we have
${T_1} + {T_2} = 0.4 \times 9.8 + 0.1 \times 9.8 = 4.9....(ii)$
Multiply eqn(ii) with 0.4 and add with eqn(i), we get
$
0.6{T_1} - 0.4{T_2} = 0.392 \\
\dfrac{{0.4{T_1} + 0.4{T_2} = 1.96}}{{ \Rightarrow {T_1} = 2.35N}} \\
$
Substitute the value of ${T_1}$in eqn (ii) we get,
$ \Rightarrow {T_2} = 2.55N$
Hence the tensions in the two strings are 2.35N and 2.55N.
Note: In such types of questions, we need to take care in selecting the point about which we calculate the next moment as such points should be selected to eliminate as many variables as possible.
Recently Updated Pages
Assertion The resistivity of a semiconductor increases class 13 physics CBSE
The branch of science which deals with nature and natural class 10 physics CBSE
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
How do you arrange NH4 + BF3 H2O C2H2 in increasing class 11 chemistry CBSE
Is H mCT and q mCT the same thing If so which is more class 11 chemistry CBSE