Question
The torque of a force 5 i +3 j -7 k about the origin is . If the force acts on a particle whose position vector is 2 i +2 j + k , then the value of will be :
BITSAT
Physics
Rotational Motion
2023
BITSAT 2023 (Memory Based Paper 2)
BITSAT Physics Question (2023) — Solution
Options
- A. 11 i +19 j -4 k
- B. -11 i +9 j -16 k
- C. -17 i +19 j -4 k
- D. 17 i +9 j +16 k
Answer
C. -17 i +19 j -4 k
Step-by-step solution
Given that torque, =5 i +3 j -7 k Position vector, r =2 i ++2 j + k aligned & = r F = | array ccc i & j & k \\ 2 & 2 & 1 \\ 5 & 3 & -7 array | \\ & = i (-14-3)- j (-14-5)+ k (6-10) \\ & =-17 i +19 j -4 k aligned
Related: Physics — Rotational Motion · All PYQ Banks