Impulse of a ball being thrown on to the wall

[blee2x2]

Homework Statement

a tennis ball of mass m = 0.075kg is thrown at a wall with a speed of v = 15m/s. It strikes the wall at a 45˚ angle and rebounds with the same speed at 45˚. What is the impulse given by the wall?

Homework Equations

impulse = Change in mass x Change in velocity

The Attempt at a Solution

Since the velocity is not changing once the ball rebounds from the wall the impulse is the same as it is when it strikes the wall?

 

[haruspex]

Since the velocity is not changing once the ball rebounds from the wall the impulse is the same as it is when it strikes the wall?

Velocity is a vector; it has direction. The speed does not change from the bounce, but the velocity does.
Do you know how to add and subtract vectors?