# Mechanics question in 3D

## Homework Statement

A parachutist jumps from a plane which is at position S = [0, 5000, 0] at time t = 0. The starting velocity of parachutist is v = [300, 0, 100] and we're assuming the parachutists falls like a particle with constant acceleration a = [2, -9.81, 0].

I need to find the parachutists position after 10 seconds.

## Homework Equations

the only equations i have here are the 3 for accelation under constant motion but these assume a one directional system.

## The Attempt at a Solution

i can't attempt a solution without knowing where i'm starting here with the 3 dimensions so if anyone could give me a hand with what equations i need to use then i should be good to go!

Related Introductory Physics Homework Help News on Phys.org
kuruman
Homework Helper
Gold Member
If you know what happens in 1-D, you can easily generalize to 3-D. All you need to do is change symbols. The most general expressions for constant acceleration are

x(t) = xo+voxt + (1/2)axt2
y(t) = yo+voyt + (1/2)ayt2
z(t) = zo+vozt + (1/2)azt2

In 3-D the position of the parachutist at any time t is [x(t), y(t), z(t)].

thank you so much, that's perfect.

just didn't know if we we're dealing with angular velocity or something more complicated here.

cheers!