Question

In the arrangement shown in figure $m_1=8kg,m_2=2kg$ and spring constant $K=1600N/m$. All surfaces are smooth then:
[a] Tension in string, T = 17.2N
[b] Tension in string, T = 15.68 N
[c] Extension in spring is 9.8 mm
[d] Extension in spring is 12 mm

• A. b, c
• B. b, d
• C. a, c
• D. a, d

Answer 1

The correct option is A b, c

Let the tension generated in the string be $T$.This string is connected to the spring so tension becomes equal to$Kx$, where $x$ is the elongation in the spring.

Now,equation of motion are as follows-

$m_{2}g-kx=m_{2}a$

$kx=m_{1}a$.

solvingthese equations give $kx=15.68N$,which is equal to the tension produced $T$.

Also $x$ comes out to be $9.8mm$.

(Value of $g$ is $9.8m{s}^{-2}$)