Calculus 1 : Velocity

Study concepts, example questions & explanations for Calculus 1

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Example Questions

Example Question #181 : Calculus

Find the velocity of an bullet after  seconds if its inital velocity is  ft/s and its acceleration is ft/s.

Possible Answers:

Correct answer:

Explanation:

To find the velocity of the object after a certain time, we first must find the velocity function of the object, then solve the position function at that given time.

The velocity function of an object moving with a uniform, or constant, acceleration is , where  is the inital velocity of the object and  is the acceleration of the object.

For this problem:

After  seconds, the velocity of bullet is  ft/s.

Example Question #182 : Calculus

Find the velocity function of an bullet after it has been fired if its inital velocity is  ft/s and its acceleration is ft/s.

Possible Answers:

Correct answer:

Explanation:

The velocity function of an object moving with a uniform, or constant, acceleration is , where  is the inital velocity of the object and  is the acceleration of the object.

For this problem:

 

Side note: The velocity function is the first derivative of the position function moving with a uniform acceleration 

 

 

 

Example Question #183 : Calculus

If the position of a particle is given by the function , what is its velocity at time  ?

Possible Answers:

Correct answer:

Explanation:

Velocity is the time derivative of position:

For the position function

Velocity is thus:

Example Question #181 : Calculus

The position of an animal is given by the function

.

 

At what time is the animal's velocity at its lowest? 

Possible Answers:

Correct answer:

Explanation:

Differentiating the position function will result in the function representing the animal's velocity.

Complete the square to rearrange the function as follows:

 

Notice that this function is an upward facing parabola with its vertex at .

Since the parabola is upward facing (concave up), the vertex will be a local minimum.

Therefore, the velocity is lowest at the vertex, when .

Example Question #184 : Calculus

The position of a particle is modeled by the function . At what time, , will the particle reverse directions?

Possible Answers:

Correct answer:

Explanation:

Velocity is the time derivative of position:

For the function

Velocity is thus:

There will be a change in direction of the particle after the velocity reaches zero:

Neglecting the trivial solution of , the particle will turn around at .

Example Question #186 : Calculus

Find the velocity function of a particle if its position function is  .

Possible Answers:

Correct answer:

Explanation:

The velocity function is the first derivative of the position function, or 

.

We will use the trigonometric rules, 

 and 

,

where  is a constant, to find the derivative of this position function.

For this problem:

 

Example Question #187 : Calculus

Find the velocity function of the particle given the following position function:

Possible Answers:

Correct answer:

Explanation:

The velocity function is the derivative of the position function:

and was found using the following rules:

Example Question #185 : Calculus

The function  represents the position of a particle. What will the particle's velocity when ?

Possible Answers:

Not enough information. The particle's acceleration function must be known.

Correct answer:

Explanation:

To find the function representing velocity, differentiate the position function. 

The first derivative is taken as follows:

Therefore, the velocity function is:

Next, evaluate the velocity function when .

In other words find .

Example Question #186 : Calculus

When , a pendulum is swinging at a velocity of . It accelerates according to the following function:

Find the function representing the pendulum's velocity.

Possible Answers:

Correct answer:

Explanation:

To find the function representing velocity, you must find the indefinite integral of the acceleration function.

Antidifferentiating the acceleration function is done as follows:

From the problem, you know that when , the pendulum has a velocity of . Therefore, .

Substitute these values in:

Therefore, your velocity function is:

Example Question #190 : Calculus

A car is moving with a position function

What is the velocity of the car at ?

Possible Answers:

Correct answer:

Explanation:

The velocity function is the first derivative of the position function:

and was found using the following rule:

Now, plug in the time t=0 into the velocity function:

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