JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A boy is rolling a \(0.5\, kg\) ball on the frictionless floor with the speed of \(20\, ms ^{-1}\). The ball gets deflected by an obstacle on the way. After deflection it moves with \(5 \%\) of its initial kinetic energy. What is the speed of the ball now ? (in \(ms ^{-1}\))
- A \(19.0\)
- B \(4.47\)
- C \(14.41\)
- D \(1.00\)
Answer & Solution
Correct Answer
(B) \(4.47\)
Step-by-step Solution
Detailed explanation
Given, \(m =0.5 kg\) and \(u =20 m / s\) Initial kinetic energy \(\left( k _{ i }\right)=\frac{1}{2} mu ^{2}\) \(=\frac{1}{2} \times 0.5 \times 20 \times 20=100 J\) After deflection it moves with \(5 \%\) of \(k _{ i }\)…
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