NEET 2020
- Exam
- NEET
- Year
- 2020
- Subject
- Physics
- Chapter
- Rotational Motion
NEET 2020 · Physics · Rotational Motion
Find the torque about the origin when a force of 3 ^ j N acts on a...
Find the torque about the origin when a force of 3\overset{^}{j}N acts on a particle whose position vector is 2\overset{^}{k}m.
Options
- A6\overset{^}{j}Nm
- B- 6\overset{^}{i}Nm
- C6\overset{^}{k}Nm
- D6\overset{^}{i}Nm
Correct answer
B. - 6\overset{^}{i}Nm
Step-by-step solution
\overset{\to}{F} = 3\overset{^}{j}N, \overset{\to}{r} = 2\overset{^}{k}
\overset{\to}{τ} = \overset{\to}{r} \times \overset{\to}{F} = 2\overset{^}{k} \times 3\overset{^}{j} = 6 ( \overset{^}{k} \times \overset{^}{j} )
= 6 ( - \overset{^}{i} )
\overset{\to}{τ} = - 6\overset{^}{i}Nm