Vectors

Q2. Find the resultant of two velocities, 40 m/s and 30 m/s, with an angle of 90° between them.

What is the angle between the resultant and the first velocity?

Using graph paper you can construct the vector diagram as shown above.

Make sure that you clearly indicate the scale you are using for the vector magnitude.

Also make your answer stand out clearly to the examiner.

To solve by calculation is easy as you already have the vectors in their horizontal and vertical components:

Using pythagoras:

30² + 40² = R²

R² = 2500

R = 50 m/s

The magnitude of the resultant R = 39 N

From the diagram:

tan α = 30/40 = 0.75

α = 37^o

The angle between the resultant and the first force is 37^o