We are given that:
The acceleration of free fall on a certain planet is 8m/s². An object is dropped from the height and hits the ground after 1.5sWe need to find:
Height from which the object was dropped.Using equations of motion:
➙ v² - u² = 2as
➙ v = u + at
here,
u = initial velocityv = final velocitya = accelerations = displacementt = time taken Solution:From the given information, we can conclude that:
initial velocity of the object is 0 m/sacceleration due to gravity = 8 m/s²time taken = 1.5 secondsNow, using equation of motion:
➝ v = u + at
➝ v = 0 + ( 8 × 1.5 )
➝ v = 0 + 12 .0
➝ v = 12 m/s
final velocity of object = 12 m/sFor, acceleration :
➝ v² - u² = 2as
➝ ( 12 )² - ( 0 )² = 2 × 8 × s
➝ 144 - 0 = 16s
➝ 16 s = 144
➝ s = 144 / 16
➝ s = 9m
Displacement = 9 mSince, we take displacement in terms of distance in some places, therefore we can say that the height from which the object was dropped is 9 meters .