Question

Two bullets are thrown simultaneously in the same vertical plane from same point with different speeds u₁ and u₂ at angles of projection q₁ and q₂ with horizontal such that u₁cosq₁ = u₂ cosq₂ then the path followed by one as seen from other is a –

• A. Vertical straight line
• B. Horizontal straight line
• C. Parabola
• D. Any straight line

Answer 1

Answer: (A)

Vertical straight line

Answer 2

$\overset{\rightarrow}{V_{1}}$= u₁cosq₁$\widehat{i}$ + (u₁ sinq₁ – gt)$\widehat{j}$

$\overset{\rightarrow}{V_{2}}$ = u₂ cosq₂$\widehat{i}$+ (u₂ sinq₂ – gt) $\widehat{j}$

$\overset{\rightarrow}{V_{rel.}}$=(u₁cosq₁ –u₂ cosq₂)$\widehat{i}$ + (u₁ sinq₁– u₂ sinq₂) $\widehat{j}$

as u₁ cosq₁ = u₂ cosq₂

given

$\overset{\rightarrow}{V_{rel.}}$ = (u₁ sinq₁ –u₂ sinq₂)$\widehat{j}$