84. 4 relative velocity addition and accelerations Exercise 2 The compass in an airplane indicates that it is headed due east: its air speed indicator reads 215km/h a steady wind of 65 km/h is blowing due north. (a)what is the velocity of the plane with respect to the ground?(b)If the pilot whishes to fly due east, what must be the heading? That is, what must the compass read? 84. 4 relative velocity addition and accelerations Solution: v,,+ PG PA Vn+v 65 =√2152+65 a=tan1 VAG= tan 215187o =224.6km/h (b)vaG=VP sin B cos B B=sinC=sin 9.55 215 215cos1955°=204.9km/h11 Exercise 2: The compass in an airplane indicates that it is headed due east; its air speed indicator reads 215km/h. A steady wind of 65 km/h is blowing due north. (a)What is the velocity of the plane with respect to the ground? (b) If the pilot whishes to fly due east, what must be the heading? That is, what must the compass read? §4.4 relative velocity addition and accelerations Solution: (a) 224.6km/h 215 65 2 2 2 2 = = + PG = PA + AG v v v o 18.7 215 65 tan tan 1 1 = = = − − PA AG v v α β β cos sin PG PA AG PA v v v v = (b) = o 19.55 215 65 sin sin 1 1 = = = − − PA AG V v β = 215cos19.55 = 204.9km/h o PG v §4.4 relative velocity addition and accelerations PG PA AG v v v r r r = +