Question

A vector $\overset{\rightarrow}{F_{1}}$ is along the positive x-axis. If its vector product with another vector $\overset{\rightarrow}{F_{2}}$ is zero, then $\overset{\rightarrow}{F_{2}}$ could be –

• A. $4\overset{\rightarrow}{i}$
• B. – ($\overset{\rightarrow}{i}$ + $\overset{\rightarrow}{j}$)
• C. ($\overset{\rightarrow}{j}$ + $\overset{\rightarrow}{k}$)
• D. – (4$\overset{\rightarrow}{j}$)

Answer 1

Answer: (A)

$4\overset{\rightarrow}{i}$

Answer 2

$\overset{\rightarrow}{F_{1}}$ = F₁$\widehat{i}$

$\overset{\rightarrow}{F_{1}}$ × $\overset{\rightarrow}{F_{2}}$ = 0 Ž F₁$\widehat{i}$ × (4$\widehat{i}$) = 0