# Writing Equations for Position, Velocity, and Accelerations as functions of time

## Homework Statement

A projectile is launched with a speed of 50.0 m/s and an angle of 40.0o above the horizontal, from the top of a 75.0 m high cliﬀ onto a ﬂat valley ﬂoor at the base of the cliﬀ. Assume that g = 10.0 m/s2 and ignore aerodynamic eﬀects.

Write equations for position, velocity, and acceleration as function of time for the projectile.

## The Attempt at a Solution

I've been looking through the time functions but I can't seem to figure out how to write these equations. Any help would be greatly appreciated.

## Answers and Replies

cepheid
Staff Emeritus
Science Advisor
Gold Member
It's a projectile motion problem. What is a projectile? An object that, once set into motion (launched) travels solely under the influence of gravity. Gravity is a constant force (it isn't really, but it is for our purposes, unless you're travelling really large vertical distances). So you already know that the acceleration is constant (doesn't change with time). From that you can either work backwards using calculus to find the velocity and position. OR, if you haven't studied calculus, then your teacher will have taught you kinematics formulas that *describe* the motion of an object under constant acceleration (formulas that are derived from calculus), and you can just *use* them.

I didn't really understand our teacher when he taught those formulas, is there a place I can look which teaches the formulas i'll need to use?

accident put wrong post in this forum

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