1.3) \ \
\Speed of Vehicle V vv = 125 km/h in north-east direction. \ \
\Speed of Vehicle W vw = 125 km/h in east direction. \ \
\Consider that two vehicles are starts from same point. \ \
\ \ \
By using vector analysis \ \
\OA = 125 km/h \ \
\OB = 125 km/h \ \
\OA = BC \ \
\OB = AC \ \
\AB = CD \ \
\OD = OB+BD \ \
\OC = Relative velocity magnitude \ \
\∠OCD = Relative velocity angle \ \
\From above figure \ \
\Angle ∠NOE = 90° \ \
\Angle ∠AOB is half in ∠NOE \ \
\Angle ∠AOB = ∠CBD = θ = 45° \ \
\From CBD right angled triangle \ \
\sinθ = BC/CD \ \
\BC = CD sin 45° \ \
\BC = 125 sin 45° \ \
\BC = 88.388 km/h \ \
\From CBD right angled triangle \ \
\cosθ = BD/CB \ \
\BD = CB cos 45° \ \
\BD = 125 cos 45° \ \
\BD = 88.388 km/h \ \
\OD = OB+BD = 125+88.388 = 213.388 km/h \ \
\From OAB right angled triangle \ \
\sinθ = AB/OA \ \
\AB = OA sin45 \ \
\AB = 125 sin45 \ \
\AB = 88.388 km/h \ \
\AB = CD = 88.388 km/h \ \
\From OCD right angled triangle \ \
\OC² = OD² + CD² \ \
\OC² = 213.388² + 88.388² \ \
\OC = 230.969 km/h \ \
\∠OCD = tan-1(88.388/213.388) \ \
\∠OCD = 22.3° \ \
\Solution : \ \
\Magnitude of the velocity of vehicle W relative to the velocity of vehicle V is 230.969 km/h \ \
\Direction of the velocity of vehicle W relative to the velocity of vehicle V is 22.3° upside inclined to east \ \