## chaelly13 3 years ago A football is kicked at ground level with a speed of 35.0 m/s at an angle of 33.0° to the horizontal. How much later does it hit the ground?

1. j814wong

Frist, you want to calculate the initial vertical velocity given the angle and initial velocity.

2. j814wong

Since the vertical and horizontal motions of projhectile motion should be consider seperately, you can only focus on the vertical aspect of this question and ignore the horizontal motion altogether.

3. j814wong

Once you solve that, you can use this equation. v final = (v initial)+at For the vertical motion, a is always -9.8m/s^2 which is the acceleration due to gravity.

4. j814wong

For these sorts of questions, it helps to list down quickly the information you know and the information you need to find out so you can determine which formula provides for what you have to find what you need.

5. j814wong

Once you get the time to go up, you multiply the time by 2 since the time to go up is teh same as the time to go back down assuming they start and end at teh same height.

6. j814wong

Alternatively, you can use the formula T = 2 * (initial ertical speed) / g

7. j814wong

This latter formula is a variation on the first one.