Take into account that the vertical distance traveled by the acorn can be calculated by using:
where,
g: gravitational acceleration constant = 9.8m/s^2
t: time acorn takes to hit the ground = 2.0s
h: height at which acorn is initially = ?
Replace the given values of the parameters into the previous formula and simplfiy:
Hence, the acorn was released from a high of 19.6m above the ground.
The velocity just after acorn hits the ground is given by:
Hence, the speed is 19.6 m/s