Calculus 1 : How to find distance

Study concepts, example questions & explanations for Calculus 1

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Example Questions

Example Question #101 : How To Find Distance

Find the distance travelled by a particle following the velocity function 

 from  to 

Possible Answers:

Correct answer:

Explanation:

We have to distinguish distance from displacement. If we wanted to find the displacement of the object, we would take the definite integral of velocity and solve. However, when we solve for distance, we have to solve for the integral of 

We take the absolute value because distances can never be negative. 

Taking the integral of an absolute value function is difficult, instead we will do separate integrals for when  is positive and negative between  and .

  from  to 

 from  to 

We can express the distance travelled  as

We split it up into two integrals because the sign of the integral would change, which is compensated for by the absolute value. 

Firstly, recall that

Also recall that

Knowing these two identites, we can solve for 

Solving for ,

 

Example Question #102 : How To Find Distance

A ball has been thrown out of the window of a skyscraper, which is at the highest point of the function.  The function  describes the motion of the ball, where  is the height and  represents the horizontal distance.  What is the distance from the building to where the ball has hit the ground?

Possible Answers:

Correct answer:

Explanation:

There are two things we will need to solve for.  First is the vertex of the parabola, and second is where the ball will hit the ground.

Use the FOIL method to simplify the binomials of the height function.

Recall the vertex formula for the parabola to find the max.  Substitute the values of  and  since the height function is in standard form.

This is the position of the ball that is thrown from the skyscraper.

We will now need to know the roots of the function.  This is where the ball hits the ground.  Set the height function equal to zero and solve for the roots.

Since there is no such thing as negative distance, we will only consider the positive distance .  This is where the ball has hit the ground.

Subtract  from where the ball has been thrown from  where the ball has hit the ground.  This is the horizontal distance the ball has been thrown.

Example Question #831 : Spatial Calculus

Find distance at  given the following equation:

Possible Answers:

Correct answer:

Explanation:

To solve, simply realize you were given d(t) which is the distance function. Thus, just plug in .

Example Question #104 : How To Find Distance

The velocity of a car in miles per hour can be described with the function 

.

How many miles did the car travel between  and  hours?

Possible Answers:

There is not enough information to determine the solution.

Correct answer:

Explanation:

We know that distance is the difference of  positions, so we need a position function. We can find this by integrating the velocity function.

Recall to integrate this particular function we use, 

.

The car started at position , so , and we find

and . Our position function is now determined.

The distance the car traveled between  and  is the difference between the positions of the car at those  times. Hence, we have .

Example Question #105 : How To Find Distance

Find the position at  given the following velocity function.

Possible Answers:

Correct answer:

Explanation:

To solve, simply integrate  to find , the position function, and then plug in .

Example Question #106 : How To Find Distance

The velocity of a particle is given by the function . How far does the particle travel over the interval of time 

Possible Answers:

Correct answer:

Explanation:

Velocity is the time derivative of position, and by that token position can be found by integrating a known velocity function with respect to time:

Now, if this integral were to be taken over an interval of time , this will give a finite value, a change in position, i.e. a distance travelled:

For the velocity function

The distance travelled can be found via knowledge of the following derivative properties:

Derivative of an exponential: 

The distance travelled over  is:

Pretty speedy.

Example Question #107 : How To Find Distance

The velocity of a particle is given by the function . How far does the particle travel over the interval of time  ?

Possible Answers:

Correct answer:

Explanation:

Velocity is the time derivative of position, and by that token position can be found by integrating a known velocity function with respect to time:

Now, if this integral were to be taken over an interval of time , this will give a finite value, a change in position, i.e. a distance travelled:

For the velocity function

The distance travelled can be found via knowledge of the following derivative properties:

 

Trigonometric derivative: 

The distance travelled over  is:

 

Example Question #108 : How To Find Distance

The velocity of a particle is given by the function . How far does the particle travel over the interval of time  ?

Possible Answers:

Correct answer:

Explanation:

Velocity is the time derivative of position, and by that token position can be found by integrating a known velocity function with respect to time:

Now, if this integral were to be taken over an interval of time , this will give a finite value, a change in position, i.e. a distance travelled:

For the velocity function

The distance travelled can be found via knowledge of the following derivative properties:

Trigonometric derivative: 

The distance travelled over  is:

 

Example Question #109 : How To Find Distance

A young businessman goes to New York to try and find a job. When he gets to New York, he goes to the tallest building he can find. When he's at the top, he drops a penny off the side. 15 seconds later he hears someone yell "OW!!" and looks down to see a man on his balcony rubbing his head in pain.

Assuming that the acceleration due to gravity is equal to 10 m/s2, and that the initial velocity was equal to zero, how far did the penny travel before hitting the poor guy in the head?

Possible Answers:

Correct answer:

Explanation:

The acceleration of the penny is equal to 10 m/s2, meaning that every second that passes by, the velocity will increase by 10 m/s. In order to find a formula for the velocity of the penny, you must find the anti-derivative of the acceleration. Taking the anti-derivative of the veloctity will then give you a formula for the position of the penny. 

.

Since the initial velocity was zero, you can use this initial condition to solve for the constant C. Setting 10t + C equal to zero, C is solved to be equal to 0.

Therefore, .

This makes sense, since every second that passes by, the velocity will increase by 10.

.

The final integration (anti-derivative) yields this formula. Since we are only trying to find the distance traveled, and not its exact postion, the constant C is equal to zero.

Therefore, .

In order to find the total distance traveled, plug in the amount of time that passed into the postion formula you just found!

 meters traveled.

Example Question #110 : How To Find Distance

A gohper tortoise is walking down a straight road. The tortoise's velocity, measured in m/s, is modelled by the equation:

How many meters has the gopher tortoise travelled after 20 seconds?

Possible Answers:

Correct answer:

Explanation:

To find distance traveled, we will integrate the velocity function:

To integrate use the following rule,

Thus we get the following.

 

Then, plugging in t=20

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