1) A plane is flying east relative to the ground at 110 m/s. The plane encounters a strong southerly wind of 35 m/s. Calculate the velocity of the plane relative to an observer on the ground:

2) A boat at a rowing regatta is rowing west across a river at 7.2 m/s relative to the water. The tide is flowing north at 3.5 m/s. Calculate the velocity of the rower relative to the spectators on the bank:

3) Two cars are approaching an intersection. Car 1 is travelling north at 40 km/hr and car 2 is travelling west at 60 km/hr. Calculate the velocity of car 1 relative to car 2 in m/s:

4) Ground control observes a plane heading south at 80 m/s. The wind sock at the airport records a wind speed of 20 m/s west. Calculate the velocity of the plane relative to the wind: