PHY KINEMATICS TEST REVIEW

What are the three fundamental SI units?

Meter (m), kilogram (kg), second (s)

What is displacement?

Change in position: Δx = xf − xi

Is displacement a scalar or vector?

Vector

What is velocity?

Rate of change of position: v = dx/dt

What is average velocity?

vavg = Δx/Δt

What is speed?

Magnitude of velocity; always positive

What is acceleration?

Rate of change of velocity: a = dv/dt

What is average acceleration?

aavg = Δv/Δt

How do you find velocity from acceleration?

v = ∫a dt

How do you find position from velocity?

x = ∫v dt

Constant acceleration equation for final velocity?

vf = vi + at

Constant acceleration equation for position?

x = vit + ½at²

Constant acceleration equation without time?

vf² = vi² + 2ax

What are the two key ideas of 2-D kinematics?

Horizontal and vertical motions are independent; motion can be represented with vectors.

How do you find the x-component of a vector?

Ax = A cos θ

How do you find the y-component of a vector?

Ay = A sin θ

How do you find the magnitude of a vector?

|A| = √(Ax² + Ay²)

How are vectors added?

Add x-components and y-components separately.

What is the position vector?

r⃗ = xî + yĵ

What is the velocity vector?

v⃗ = dr⃗/dt

What is the acceleration vector?

a⃗ = dv⃗/dt

What is relative velocity?

Velocity measured with respect to a reference frame.

Relative velocity formula?

v⃗AC = v⃗AB + v⃗BC

SI unit of position?

m

SI unit of velocity?

m/s

SI unit of acceleration?

m/s²

SI unit of mass?

kg

SI unit of time?

s

In projectile motion, what is usually the horizontal acceleration?

0 m/s²

In projectile motion, what is the vertical acceleration near Earth?

−9.8 m/s²

Derivative of position equals?

Velocity

Derivative of velocity equals?

Acceleration

Integral of acceleration equals?

Velocity

Integral of velocity equals?

Position

If an object is accelerating toward a point, then it must be getting closer and closer to that point.

False

Suppose that a car traveling in the -x direction begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct?

The acceleration must be in the +x direction.

Suppose that a car traveling in the +x direction begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct?

The acceleration must be in the -x direction.

Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object 

The magnitude of the displacement can be less than or equal to the distance traveled.

For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration 

is always zero

For general projectile motion with no air resistance, the horizontal component of a projectile's velocity 

remains a zero constant

What quantity is represented by the slope of a position-versus-time graph?

Velocity

What quantity is represented by the slope of a velocity-versus-time graph?

Acceleration

When a ball is thrown straight up with no air resistance, the acceleration at its highest point is

downwards