Kinematic Motion

[vinniekan]

---

Members don't see this ad.

So for some reason I'm stuck in the question and I can't seem to figure it out

"A bottle is thrown with an initial velocity of 4m/s at 45° from the horizon. Find its final horizontal and vertical velocities before striking the ocean"

The answer is 2.8m/s for both h & v direction, but no solution to show how to get it

What i'm confused I thought that if you break a velocity vector in both x and y, the x velocity doesn't change is there is no acceleration in the x direction, so should the final velocity be 4cos45 = 2.1 ish?

If anybody can point to how to solve that problem that would be great. I looked at every equation you can use and there is at least 2 unknowns in each of them 😕

 

[dr seuss]

I'm not sure how you got 4cos45 = 2.1. It equals 2.8. V👍 initial is 4sin45 = 2.8. V👍 final is the same magnitude but opposite direction. It goes up then comes back down at the same speed since the y inital and final are both the same (0).

 

[vinniekan]

effing google, i just typed in cos 45 in google and it gave me 0.52ish

so i assumed it was right...

i went back and checked the actual value, you were right, thanks a bunch, i thought i was an idiot and couldn't solved such a simple kinematic problem