Answer to Question #347817 in Mechanics | Relativity for PAUL JOSHUA 123

Question

The formula h (t) = -4.9t² + 20t+ 80 gives the height (h) above ground in meter (m) of an object thrown at t=0, straight upwards from the top of a tower 80m height.

1)What is the height point reached by the object ?

2) After how many seconds does the object hit the ground?

This question is based on projectile.

Answer 1

$h'=-9.8t+20,$

$t_0=2.04~s,$

$h(t_0)=20.4~m,$

$t=2.5~s.$