Study guides › C/P › Physics
Kinematics
Kinematics describes motion without asking what causes it. You will work with vectors, velocity and acceleration, the constant-acceleration equations, motion graphs, free fall, and projectiles, all with numbers you can do by hand.
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What this chapter covers
- Vectors, Distance & Displacement. Half of kinematics is knowing which quantities have a direction; the MCAT tests this constantly.
- Velocity & Acceleration. Average versus instantaneous, and the sign of acceleration relative to velocity, drive most conceptual kinematics questions.
- Kinematic Equations & Free Fall. Four equations solve every constant-acceleration problem; pick the one that lacks the variable you do not need.
- Graphs of Motion. Slope and area on x-t, v-t, and a-t graphs are a favorite way to test kinematics without any algebra.
- Projectile Motion. Split projectile motion into a constant-velocity horizontal part and a free-fall vertical part, then link them with time.
Key points to know
- Vectors have direction; scalars do not
- Displacement = final position − initial position, independent of the path
- Average velocity = displacement / time; average speed = distance / time
- a = Δv/Δt, units m/s²
- Kinematic equations require constant acceleration
- Choose the equation that omits the variable you neither know nor need
- x-t slope = velocity
- v-t slope = acceleration; v-t area = displacement
Try a practice question
Which of the following is a vector quantity?
- Distance
- Speed
- Displacement
- Time
Show the answer
C. Displacement has both magnitude and direction. Distance, speed, and time are scalars; a common slip is calling speed a vector because it sounds like velocity.
Common questions
What does this chapter cover?
Kinematics covers Vectors, Distance & Displacement, Velocity & Acceleration, Kinematic Equations & Free Fall, Graphs of Motion, Projectile Motion.
What should I know first?
Vectors have direction; scalars do not Displacement = final position − initial position, independent of the path Average velocity = displacement / time; average speed = distance / time
24 original practice questions accompany this chapter in the app. Spaced review brings missed ideas back at the right time; it helps memory but cannot promise you will not miss an idea again.