Cogito
Multivariable Calculus · Chapter 2 · Lesson 2
Velocity and Acceleration
Differentiate each component and get motion.
12 problems · about 23 minutes · N-VM.A.1
Figure — use these to answer the problems
- Point(2, 4)
- Slope of the tangent4
Warm Up
Straightforward practice. Get the method working first.
5 problemsr(t) = ⟨t², 2t, 0⟩. What is the y-component of velocity?
AnswerHow do velocity and speed differ?
- Velocity is a vector; speed is its magnitude.
- They are two names for the same thing.
r(t) = ⟨t³, t, 0⟩. What is the x-component of velocity at t = 2?
Answerr(t) = ⟨t³, t, 0⟩. What is the x-component of acceleration at t = 2?
Answerr(t) = ⟨5t, 0, 12t⟩. What is the speed?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsVelocity is ⟨0, 0, 0⟩ at some t. Has the particle stopped? 1 yes, 0 no.
AnswerA velocity vector of magnitude 9. What is the magnitude of the unit tangent?
Answerr(t) = ⟨7t, −4, 0⟩. What is the y-component of velocity?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsMatch each quantity to its description.
Draw a line from each item on the left to its match on the right.
- Velocity
- Speed
- Acceleration
- The first derivative, a vector
- The magnitude of the first derivative, a number
- The second derivative, a vector
A particle on a circle at constant speed. Is its acceleration zero? 1 yes, 0 no.
AnswerThe Drone Path
r(t) = ⟨t², 6t, 0⟩. What is the x-component of velocity at t = 5?
AnswerThe Straight Run
r(t) = ⟨6t, 8t, 0⟩. What is the speed?
Answer