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?
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.