(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A particle moves along the x axis. Its position is given by the equation x=1.5+2.50t-3.9t^2 with x in meters and t in seconds.

a. Determine its position when it changes direction

b. what is its velocity when it returns to the position it had at t=o

2. Relevant equations

3. The attempt at a solution

a. I would need to take the derivative and set it equal to 0, right?

f'(x)=2.50-7.8t=0

t=(-2.5/-7.8)

I then need to plug t back into the original equation, right?

Would the position when it changes direction be 1.80?

b. What is the velocity when it returns to the position it had at t=0?

2.50-7.8(0)=2.5

Thank you very much

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Particle problem

**Physics Forums | Science Articles, Homework Help, Discussion**