Formulas a utilizar :
<img src="https://tex.z-dn.net/?f=v%3D%20%5Csqrt%7B%28vx%29%20%5E%7B2%7D%20%2B%20%28vy%29%5E2%20%7D%20" />
<img src="https://tex.z-dn.net/?f=vx%3Dvox%20%5C%5C%20vy%3Dvoy%2Bgt%20%5C%5C%20voy%3Dvo%2Asen%20%5Calpha%20" />
<img src="https://tex.z-dn.net/?f=vox%3Dvo%2Acos%20%5Calpha%20" />
<img src="https://tex.z-dn.net/?f=x%20%3D%20vox%2At" />
Operamos
<img src="https://tex.z-dn.net/?f=vox" />
<img src="https://tex.z-dn.net/?f=vox%3Dvo%2Acos%20%5Calpha%20%20%5C%5C%20vox%3D100m%2Fs%20%2A%20cos45%20%5C%5C%20vox%3D100m%2Fs%20%2A%200.7%20%5C%5C%20vox%3D70.71m%2Fs" />
Ya sabemos que<img src="https://tex.z-dn.net/?f=vx%3D70.71m%2Fs" />
Operamos
<img src="https://tex.z-dn.net/?f=voy%20%3D%20vo%20%2A%20sen%20%5Calpha%20%20%5C%5C%20voy%3D100m%2Fs%20%2A0.70%20%5C%5C%20voy%3D70.71m%2Fs" />
Operamos
<img src="https://tex.z-dn.net/?f=vy%3Dvoy%2Bgt%20%5C%5C%20vy%3D70.71m%2Fs%20%2B%209.8m%2Fs%5E2%20%2A%2014.43s%20%5C%5C%20vy%3D70.71m%2Fs%2B141.42m%2Fs%20%5C%5C%20vy%3D212.13m%2Fs" />
Para sacar el vector de velocidad resultante
<img src="https://tex.z-dn.net/?f=v%20%3D%5Csqrt%7B%28vx%29%5E2%2B%28vy%29%5E2%7D%20%20%5C%5C%20v%3D%5Csqrt%7B4999.90%2B4999.90%7D%20%5C%5C%20v%3D%5Csqrt%7B9999.8%7D%20%5C%5C%20v%3D99.99%20m%2Fs" />
Posicion a los 3s
[img = 10]
Posicion a los 8s
[img = 11]
Espero 5 estrellas y si tienes alguna duda no hesites en preguntarme : ).