Answer with Explanation:
We are given that
[tex]Force,F=4.0 jN[/tex]
Mass of object,m=0.25 kg
Position vector,r=[tex](2.0i-2.0k) m[/tex]
Velocity vector,v=[tex](-5.0 i+5.0 k) m/s[/tex]
a.We have to find the angular momentum of object.
Angular momentum with respect to origin is given by
[tex]l=m(r\times v)[/tex]
Using the formula
[tex]l=0.25((2i-2k)\times (-5i+5k))[/tex]
[tex]l=0.25\times\begin{vmatrix}i&j&k\\2&0&-2\\-5&0&5\end{vmatrix}[/tex]
[tex]l=0.25(-j)(10-10)=0[/tex]
b.Torque acting on the object,[tex]\tau=r\times F[/tex]
[tex]\tau=(2i-2k)\times 4j=(8i\times j-8k\times j)=(8k+8i)Nm[/tex]
Where [tex]i\times j=k,k\times j=-i[/tex]
[tex]\tau=(8i+8k) Nm[/tex]