Work Energy and Power - Result Question 20

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23. A ball of mass $2 kg$ and another of mass $4 kg$ are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

======= ####23. A ball of mass $2 kg$ and another of mass $4 kg$ are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/work-energy-and-power/work-energy-and-power—result-question-20.md (a) $1: \sqrt{ } 2$

(b) $\sqrt{ } 2: 1$

(c) $1: 4$

(d) $1: 2$

[2004]

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Answer:

Correct Answer: 23. (d)

Solution:

  1. (d)

Since height is same for both balls, their velocities on reaching the ground will be same.

$ \therefore \frac{K \cdot E_1}{K \cdot E_2}=\frac{\frac{1}{2} m_1 v_0^{2}}{\frac{1}{2} m_2 v_0^{2}}=\frac{m_1}{m_2}=\frac{2}{4}=\frac{1}{2} $