Answer:
Velocity of plane B with respect to plane A is 356.21 km
Explanation:
Velocity of plane A [tex]v_{A}=500 km/hr[/tex]
Velocity of plane B [tex]v_{B}=700 km/hr[/tex]
Angle between the their straightline is [tex]\theta =60 ^0[/tex]
velocity of plane B with respect to plane A is given by
[tex]V_{BA}= V_{B}sin \theta - V_{A}cos\theta\\V_{BA}= 700 \times sin 60 - 500\times cos60\\V_{BA}=606.21-250\\V_{BA}=356.21 km[/tex]
Velocity of plane B with respect to plane A is 356.21 km