Question

Two blocks P and Q of masses 0.3 kg and 0.4 kg, respectively, are stuck to each other by some weak glue as shown in the figure. They hang together at the end of a spring with a spring constant of k = 200 N/m. The block Q suddenly falls free due to the failure of glue, then the maximum kinetic energy of block P during subsequent motion will be ______ mJ.

 

विकल्प

• 10.00

• 20.00

• 30.00

• 40.00

Answer 1

Two blocks P and Q of masses 0.3 kg and 0.4 kg, respectively, are stuck to each other by some weak glue as shown in the figure. They hang together at the end of a spring with a spring constant of k = 200 N/m. Block Q suddenly falls free due to the failure of glue, then the maximum kinetic energy of block P during subsequent motion will be 40.00 mJ.

Explanation:

A = `(0.4g)/200`

= 2 cm motion starts from the lower extremity.

`KE_max = 1/2momega^2A^2`

= `1/2 xx 0.3 xx k/m A^2`

= `1/2 xx 0.3 xx 200/0.3 xx (2/100)^2`

= 0.04 J

= 40 mJ