To calculate this, you divide the change in velocity, by the time.
It is 66.66... (repeating) metres per second2.
the magnitude of the skydivers acceleration is zero as he is decelerating by opening his parachute!
66.7 m/s2
80 m/s2 up
Only if they have a heart attack, but not likely.
66.7 m/s2
66.7 m/s2
80 m/s 2 up
Maximum speed is about 220 to 230mph and can be achieved after about 20 seconds of freefall. Normal parachute opening speed should be not greater that 120mph to avoid damage to the parachute
If the 0.75 refers to seconds, then his acceleration is -66.66... (repeating) metres per second^2.
He will decelerate (meaning an acceleration in the direction opposite of current velocity) at a rate of (54 m/s - 4 m/s)/.75 seconds = 66.67 m/s2. This is about 6.8 Gs.
(4 m/s - 54 m/s)/0.75 s = -50/0.75 m/s² = -200/3 ≈ - 66.67 m/s² (negative because he is decelerating)
Skydivers in different freefall orientations fall at different speeds:Wingsuiting - 25 to 60mphBelly to earth - typical for formation skydiving - 120mphFreefly headup and headdown - 150 to 190mphSpeed skydiving - 200 to 327mphFor each of these disciplines, experience, jumpsuit worn, weight & height all make subtle differences to exact freefall speeds. During any typical skydive, speeds vary a lot.