Is the ball's speed increasing?

[Westin]

Homework Statement

The figure below shows a moving ball, its momentum, and the net force acting on it an instant in time.

At this instant, the ball's speed is:

1) not changing [/B]
2) decreasing
3) increasing

Homework Equations

None.

The Attempt at a Solution

My guess would be that the balls speed is increasing since the force and change of momentum both go towards + x direction but I'm not totally sure, any help?[/B]

 

[Orodruin]

Correct, but you could formalise your answer a bit. It is possible that the momentum and force both have positive components in the x direction and have decreasing speed. The real issue is about the angle between the force and momentum vectors.

 

[Westin]

Correct, but you could formalise your answer a bit. It is possible that the momentum and force both have positive components in the x direction and have decreasing speed. The real issue is about the angle between the force and momentum vectors.

That makes sense, if the force was pointed straight down instead, would the ball's speed then be slowing down?

 

[Orodruin]

That makes sense, if the force was pointed straight down instead, would the ball's speed then be slowing down?

Given the same momentum, yes.