# What is the average launch speed?

1. Oct 21, 2016

### Angela_vaal

1. The problem statement, all variables and given/known data
During several practice runs you stand at the end of a diving board and launch the basketball horizontally from a position 4.50 m above the water. If the average landing spot is6.25 m horizontally from your initial position, what is the average launch speed?

2. Relevant equations

3. The attempt at a solution
avg speed=total distance/total time. but time is not stated? where do i start ?! i attached the photo of the problem

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2. Oct 21, 2016

### haruspex

By thinking about the vertical motion. What do you know about the vertical components of initial and final speeds, time, distance and acceleration? From the items you know, what else can you calculate?

3. Oct 21, 2016

### Angela_vaal

would I calculate time using the formula y=y1+v1t-(1/2)gt^2?

4. Oct 21, 2016

### haruspex

What do you think?

5. Oct 21, 2016

### Angela_vaal

I'm thinking I have to calculate time somehow to get the average speed. But if i use this equation, I'm not sure how I will use this equation if I don't have the initial velocity.

6. Oct 21, 2016

### haruspex

You just need the initial vertical component of velocity: