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#vector cross product

5 public questions tagged with this topic.

A 3kg particle moves with velocity v\=6i^m/s at r\=2j^m. What is the magnitude of its angular momentum about the origin?

L = r×p = |i^j^k^020600| = k^(0×0−2×6) = −12k^kg m2/s. Magnitude = 12kg m2/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 12 kg m²/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A 4kg particle moves with velocity v\=−5i^+2j^m/s at r\=3i^m. What is the z-component of its angular momentum?

L = r×p = |i^j^k^300−520| = k^(3×2−0×(−5)) = 6k^kg m2/s. Z-component = 6kg m2/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 6 kg m²/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A force F\=6i^−2j^N acts at r\=3i^+4j^m. What is the magnitude of the torque about the origin?

τ = r×F = |i^j^k^3406−20| = k^(3×(−2)−4×6) = k^(−6−24) = −30k^Nm. Magnitude = 30Nm. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 30 Nm. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A 2kg particle moves with velocity v\=4i^+5j^m/s at r\=−3j^m. What is the z-component of its angular momentum?

L = r×p = |i^j^k^0−30450| = k^(0×5−(−3)×4) = 12k^kg m2/s. Z-component = 12kg m2/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 12 kg m²/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.