Finding the impact angle when a particle hits a wall

[AdnamaLeigh]

A particle travels btwn 2 parallel vertical walls separated by 6.7m. It moves towards the opposing wall at a constant rate of 5.3m/s. It hits the opposite wall at the same height. The acceleration of gravity is 9.8m/s^2.

The first question pertaining to this was the speed when it hits the opposing wall. I found the correct answer to be 8.152m/s. Then it wants to know the angle that it hits the wall. For where the particle left the first wall, I made a right triangle and found the angle to be 49.447 degrees.

I don't know how to answer the question. I assumed that the answer was to be in respect to the positive x-axis so I did 180-49.447 = 130.553 and that was wrong. Are they asking for the angle relative to the opposing wall? I'm so confused.

 

[Doc Al]

What they want is the angle that the trajectory makes with the wall. Since the wall is vertical, the angle is with respect to vertical, not the x-axis.

 

[HallsofIvy]

" It hits the opposite wall at the same height. "

Same height?? Same as what? No height is mentioned.

Also you say "It moves towards the opposing wall at a constant rate of 5.3m/s." That can't be true if there is acceleration due to gravity.

Did you intend to say that the horizontal component of velocity is a constant 5.3 m/s?