Work Energy And Power Question 155

Question: A mass of 10 gm moving with a velocity of 100 cm/s strikes a pendulum bob of mass 10 gm. The two masses stick together. The maximum height reached by the system now is $ (g=10m/s^{2}) $ [MP PET 1993]

Options:

A) Zero

B) 5 cm

C) 2.5 cm

D) 1.25 cm

Show Answer

Answer:

Correct Answer: D

Solution:

Initially mass 10 gm moves with velocity 100 cm/s \

Initial momentum = 10 × 100 = $ 1000\frac{gm\times m}{\sec } $

After collision system moves with velocity $ {v _{sys\text{.}}} $

then Final momentum = $ (10+10)\times {v _{sys\text{.}}} $

By applying the conservation of momentum 10000 = $ 20\times {v _{sys\text{.}}} $

therefore $ {v _{sys\text{.}}}==50\ cm/s $

If system rises upto height h then $ h=\frac{v _{sys\text{.}}^{2}}{2g}=\frac{50\times 50}{2\times 1000}=\frac{2.5}{2}=1.25\ cm $



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक