If the projection of 2 i+4 j-2 k on i+2 j+α k is zero. Then, the value of α will be _ _ _ _ _ _.

Kinematics: JEE Main 2022 Physics question

JEE Main 2022 · 28 Jul, Morning shift · Q73

JEE Main 202228 Jul, Morning shiftPhysicsMediumKinematics177× since 2002

If the projection of

2 \hat{i}+4 \hat{j}-2 \hat{k}

\hat{i}+2 \hat{j}+\alpha \hat{k}

is zero. Then, the value of

\alpha

will be ___________.

Your answerType your answer. Integers and decimals are accepted.