JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A particle which is experiencing a force, given by \(\vec F = 3\vec i -12\vec j\), undergoes a displacement of \(\vec d = 4\vec i\) . If the particle had a kinetic energy of \(3\, J\) at the beginning of the displacement, what is its kinetic energy at the end of the displacement?
- A \(9\, J\)
- B \(12\, K\)
- C \(10\, J\)
- D \(15\, J\)
Answer & Solution
Correct Answer
(D) \(15\, J\)
Step-by-step Solution
Detailed explanation
\(\begin{array}{l} K.E.\, - 3 = \overrightarrow F .\overrightarrow d \\ K.E. = 3 + \left( {3\hat i - 12\hat j} \right) \times \left( {4\hat i} \right)\\ K.E. = 3 + 12 = 15\,J \end{array}\)
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