Problem Solving Process
- Use Pythagorean theorem to find out the horizontal velocity, using the given angled velocity and the project angle.
- According to the property that the vertical velocity at the highest point of the projectile is 0 m/s to find out the time the projectile takes to go from the starting point to the highest point.
- According to the property that the amounts of time that the projectile takes to go from the starting point to the highest point and back down to the same height with the start point are the same to find the its whole time traveling in the air.
- Plug the data in equation and solve for the problem.
Notice
- Launched angle:
- 45° is the launched angle which can make the projectile go farthest.
- The bigger the launched angle, the higher the projectile reach vertically, the bigger the vertical velocity, the longer the time it stay in air.
- The smaller the launched angle, the bigger the horizontal velocity.
- There are up and down motions in the same problem, so 1 direction (down) is negative.
- The initial velocity is a combination of its components.