Question

tembakan dilepaskan keatas dengan kelajuan 2 m/s. Berapa lama peluru tersebut mencapai tinggi maksimum?
(9 = 9,8 m/s² = 10 m/s²)​

Answer 1

Kinematics!

Facts:

1) an object thrown upwards, flies until it get stopped by gravity.

2) at this moment its velocity is 0 and the gravity acceleration is constant and against the moviment (its vector is backward).

Equations

$V_{f} = V_{i} + g\cdot t\\\\V_{i}\ ->\ initial\ vel.\\\\V_{f}\ ->\ final\ vel.\\\\t\ ->\ time\ instant$

Solution:

$0=2-10\cdot t\\\\10\cdot t=2\\\\t=\frac{2}{10} = 0,2\ s$

Hence, it approach the maximum height at 0,2 seconds.