Answer to Question #215801 in Physics for Aru

Question

How can you throw a projectile so that it has zero speed at the top of its trajectory? So that it has nonzero speed at the top of its trajectory?

Answer 1

1. How can you throw a projectile so that it has zero speed at the top of its trajectory?

If you throw any object with the angle to the horizontal, it moves with the same horizontal speed until lands (neglecting the air resistance). The vertical speed decreases as the object rises and comes to zero at the top of its trajectory (see https://courses.lumenlearning.com/boundless-physics/chapter/projectile-motion/). Thus, in order to elimitane the horizontal part of the speed, one should throw the projectile directly vertically (90 degrees with the horizontal).

2. So that it has nonzero speed at the top of its trajectory?

Considering the facts above, it is enough to throw the projectile with some angle (other than 90 degrees) with the horizontal.

Answer. 1) 90 degrees with the horizontal, 2) Any angle except 90 degrees with the horizontal.