# What is the direction of the change in velocity of the ball?

1. Mar 9, 2006

### rachael

9 A softball of mass 0.15 kg travelling at a speed of
16 m s–1 is struck so that it moves away from the bat at
an angle of 45° to its original direction and with the
same speed.
a What is the direction of the change in velocity of the
ball?
how do u work this question out ?
the book told me to use mgsinX/m
when i tried to do it it does not give the correct answer

thank you

2. Mar 9, 2006

### vaishakh

The direction of the change in velocity must be in the direction of the final velocity of the ball since the ball changes its direction to opposite side. Can you clear the all questions?

3. Mar 9, 2006

### topsquark

To find the change in velocity, remember that velocity is a vector. So:
$$v_0+\Delta v = v$$ by definition
$$\Delta v = v+(-v_0)$$ where -v0 is a vector of length v0 in the opposite direction to the vector v0.

So assume v0 is pointing along the +x axis. Then v is pointing at 45 degrees above the -x axis. $$\Delta v$$ is a vector pointing from the head of v0 to the head of v. Using components you should be able to find the components of the change in velocity.

-Dan