Question

Two blocks P and Q of masses 0.3 kg and 0.5 kg are hanging on a spring balance with light pan. The spring constant of the spring 100 N/m. The block Q is suddenly removed. The amplitude of resulting oscilliation is

• A. 10 cm
• B. 3 cm
• C. 5 cm
• D. 8 cm

Answer 1

The correct option is D 8 cm

Case - 1

$K=100N/m$

Case - 2 (When $Q$ block is removed)

The amplitude of resulting oscillation $=?$

Case - 1

$x_1=\frac{F_{applied}}{K}$

$=\frac{(0.3+0.5)\times \left(9.80\right)}{100N/m}$

$=\frac{0.8\times 9.80}{100}=0.0784m$

Case - 2

$x_2=\frac{F_{applied}}{K}$

$=\frac{\left(0.3\right)\left(9.80\right)}{100}$

$=0.0294m$

$\therefore$ $x^1=\sqrt{x_1^2+x_2^2}$

$=\sqrt{{0.0784}^2+{0.0294}^2}$

$=\frac{0.083}{100}m=8cm$