An object is thrown vertically upward from the ground, if it reaches a height of 18 meters in 3 seconds, at what speed was the object thrown?

1 answer

To find the initial velocity at which the object was thrown, we can use the following equation of motion for an object thrown vertically upward:

v = u + gt

Where:
v = final velocity (0 m/s at maximum height)
u = initial velocity (what we need to find)
g = acceleration due to gravity (approximately 9.81 m/s^2)
t = time taken (3 seconds)

We can rearrange this equation to solve for initial velocity:

0 = u + (9.81 m/s^2) * 3s
0 = u + 29.43

u = -29.43 m/s

Therefore, the object was thrown upward at an initial speed of 29.43 m/s.