Question

A pebble is thrown vertically upwards with a speed of 20 mps. how high it will be after 2s ?g=10

Answer 1

Hi there,

Let's solve it:

S = ut + 1/2 gt^2

=20×2+1/2×-10×2^2
=20m

Answer 2

Given,

u =20m/s

t=2s

g = -10m/s2 (because object is moving upward but g is downward always)

h= ut+1/2at2

= 20 * 2s + 0.5* (-10)* (2)2

= 40 - 20 

= 20 m