An explosion blows a rock into three parts. Two parts go off at right angles to each other. These two are, 1 kg first part moving with a velocity of 12 m s⁻¹ and 2 kg second part moving with a velocity of 8 m s⁻¹. If the third part flies off with a velocity of 4 m s⁻¹, its mass would be:

Question

Dr. Abubacker · Accepted Answer

[Solution from source] Momenta of the two pieces are 1 × 12 = 12 and 2 × 8 = 16 kg m s⁻¹ at right angles, with resultant √(12² + 16²) = 20 kg m s⁻¹. The third piece must carry an equal and opposite 20 kg m s⁻¹, so m = 20/4 = 5 kg. Answer (4).

Q. An explosion blows a rock into three parts. Two parts go off at right angles to each other. These two are, 1 kg first part moving with a velocity of 12 m s⁻¹ and 2 kg second part moving with a velocity of 8 m s⁻¹. If the third part flies off with a velocity of 4 m s⁻¹, its mass would be:

Explanation

Reviewed by Dr. Abubacker

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