Oscillations - Result Question 44

48. A mass of 2.0kg is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released the mass executes a simple harmonic motion. The spring constant is 200N/m. What should be the minimum amplitude of the motion so that the mass gets detached from the pan (take g=10m/s2 )?

(a) 10.0cm

(b) any value less than 12.0cm

(c) 4.0cm

(d) 8.0cm

[2007]

Show Answer

Answer:

Correct Answer: 48. (a)

Solution:

  1. (a) Mass gets detached at the upper extreme position when pan returns to its mean position.

At that point, R=mgmω2a=0

i.e. g=ω2a

a=g/ω2=mg/k

a=2×10200[As=ω2=km]

a=1/10m=10cm



NCERT Chapter Video Solution

Dual Pane