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AP EAMCET · PHYSICS · Laws of Motion

A force \((2 \hat{\mathbf{i}}+\hat{\mathbf{j}}-\hat{\mathbf{k}}) \mathrm{N}\) acts on a body, which is initially at rest. At the end of \(20 \mathrm{~s}\) the velocity of the body is \((4 \hat{\mathbf{i}}+2 \hat{\mathbf{j}}-2 \hat{\mathbf{k}}) \mathrm{ms}^{-1}\), then the mass of the body is

  1. A \(8\ kg\)
  2. B \(10\ kg\)
  3. C \(5\ kg\)
  4. D \(4.5\ kg\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(10\ kg\)

Step-by-step Solution

Detailed explanation

\(|\mathrm{F}|=F=\sqrt{4+1+1}=\sqrt{6}\) \(v=\sqrt{16+4+4}=\sqrt{24}\) Now, \(F=\frac{d p}{d t}=m\left(\frac{v-u}{t}\right)\) where, \(\mathrm{m}=\) mass of body…