1. A vehicle changes its velocity from 90 km>h to a dead stop in 10 s. Show that its acceleration in doing so is -2.5 m/s 2 . 2. A ball is thrown straight up with an initial speed of 40 m/s. (a) Show...

1. A vehicle changes its velocity from 90 km>h to a dead stop in 10 s. Show that its acceleration in doing so is -2.5 m/s²
.

2. A ball is thrown straight up with an initial speed of 40 m/s.

(a) Show that its time in the air is about 8 s.

(b) Show that the ball’s maximum height, neglecting air resistance, is about 80 m.