Question

If F= 2-3j N and r=3+2j m then
torque tou is
1) 12k 2) 13k 3) -12k 4)-13k​

Answer 1

Solution:

Question:

If F = 2i - 3j N and r = 3i + 2j m then  torque (tou) is (1) 12k (2) 13k (3) -12k (4)-13k.

Given,

$\vec{F} = 2\hat{i} - 3\hat{j}\ N\\\\\vec{r} = 3\hat{i} + 2\hat{j}\ m$

We know,

Torque is the cross product of force vector and displacement vector.

$i.e ,\vec{\tau} = \vec{r} \times \vec{F}$

$\vec{\tau} = (3\hat{i} - 2\hat{j}) \times (2\hat{i} + 3\hat{j} )$

$\vec{\tau}= -9\hat{k} - 4\hat{k}$

$\vec{\tau}= -13 \hat{k}$