Question

Question 1 (1 point)

A plane is flying north at 210 km/h with a head wind blowing 60 km/h south. What
is the resultant velocity of the plane relative to the ground?
150 km/h south
150 km/h north
270 km/h north
270 km/h south

Answer 1

The resultant velocity of the plane relative to the ground is;

150 kh/h north

Step-by-step explanation:

The flight speed of the plane = 210 km/h

The direction of flight of the plane = North

The speed at which the wind is blowing = 60 km/h

The direction of the wind = South

Therefore, representing the speed of the plane and the wind in vector format, we have;

The velocity vector of the plane = 210.
`\hat j`

The velocity vector of the wind = -60.
`\hat j`

Where, North is taken as the positive y or
`\hat j` direction

The resultant velocity vector is found by summation of the two vectors as follows;

Resultant velocity vector = The velocity vector of the plane + The velocity vector of the wind

Resultant velocity vector = 210.
`\hat j` + (-60.
`\hat j`) = 210.
`\hat j` - 60.
`\hat j` = 150.
`\hat j`

The resultant velocity vector = 150.
`\hat j`

Therefore, the resultant velocity of the plane relative to the ground = 150 kh/h north.