Troubles with projectile motion Help

[gidgetadores]

I've made a tennis ball launcher (tilted 45 degrees) for my physics class. The assignment is to calculate where the tennis ball will land horizontally and also how high it will go before falling back to the ground. The problem I am facing is that I need d(x) in order to find v(x), but i need v(x) in order to find d(x). If you know of any other equations I can use, that would be wonderful! This assignment is due tomorrow and I'm pretty desperate. Please help if you can!

 

[ideasrule]

You can't calculate either distance nor maximum height without knowing the projectile's launch speed. That said, you can find a relationship between the distance the projectile travels and initial speed. Start by calculating the time it takes to reach maximum height and work from there. Work with variables, and assume that launch speed is known.