Question

A pebble is thrown vertically upwards with A speed of 20m /s. how high will it be after 2 s take g is 9.8

Answer 1

$h= ut - \frac{1}{2} g {t}^{2}$
therefore,
h=20×2 - 1/2 × 9.8 ×2^2
= 40 - 1/2 × 9.8 × 4
= 40 - 19.6
= 20.4 m
after 2s the stone will cover 20.4 meters of height