2 - One-Dimensional Kinematics Free Online FlashCards

What does kinematics describe?

Kinematics describes motion without analyzing the forces that cause it.

What does position describe?

Position identifies an object's location relative to a chosen origin. It is represented by a coordinate such as $x$ or $y$.

What is the formula for displacement?

Displacement is the signed change in position: $\Delta x=x_f-x_i$. Its sign indicates direction.

How does distance differ from displacement?

Distance is the total path length traveled. It is a scalar and cannot be negative.

What is the formula for average velocity?

Average velocity is displacement divided by elapsed time: $\bar v=\frac{\Delta x}{\Delta t}$.

What does the tangent slope on an $x$-versus-$t$ graph represent?

Instantaneous velocity is the slope of the tangent to a position-versus-time graph at a particular instant: $v=\frac{dx}{dt}$.

How is speed related to velocity?

Speed is the magnitude of velocity: $\text{speed}=|v|$. It has no direction and is never negative.

What is the formula for average acceleration?

Average acceleration is the change in velocity divided by elapsed time: $\bar a=\frac{\Delta v}{\Delta t}$. Its SI unit is $\text{m/s}^2$.

When does an object slow down?

An object slows down when velocity and acceleration have opposite signs. A negative acceleration alone does not necessarily mean slowing down.

What does the slope of a $v$-versus-$t$ graph represent?

The slope of a velocity-versus-time graph gives acceleration. A horizontal line therefore represents constant velocity and zero acceleration.

What does area under a $v$-versus-$t$ graph give?

The signed area under a velocity-versus-time graph gives displacement: $\Delta x=\text{area under a }v\text{-versus-}t\text{ graph}$.

What does area under an $a$-versus-$t$ graph give?

The area under an acceleration-versus-time graph gives the change in velocity: $\Delta v=\text{area under an }a\text{-versus-}t\text{ graph}$.