Question

A projectile is launched straight up at 141 m/s How fast is it moving at the top of its trajectory? Suppose it is launched upward at 45° above the horizontal plane. How fast is it moving at the top of its curved trajectory?

Answer 1

`100 m/s`

Explanation:

At the top of its trajectory i.e at its highest point of motion,the projectile looses its vertical component of velocity directed upwards,so that just next to that it falls downwards due to gravity.

So,at that point it only bears its horizontal component of velocity i.e `u cos theta` , where, `u` is the velocity of projection and `theta` is the angle of projection.

So,here the value comes out to be about `100 m/s`