i need help.

Question

How does the time taken for a walk depend on how far you go?

Answer 1

Hi Jenna, D(istance) = R(ate) * T(ime). If the rate, R, remains the same, then the distance will depend on how long you walk.

 

If you vary the rate, R, the distance you walk will still depend on how long you walk.

 

Example:

 

R(ate) = 3 miles per hour

 

T(ime) = 1 hour

 

D(istance) = 3 * 1, or the distance will be 3 miles.

 

Questions?

Answer 2

This is a D-I-R-T (Distance-Is-Rate-times-Time) question.

 

Who hasn't either asked or heard that famous question, "Are we there, yet?"  And the answer is either "yy more minutes" or it is "xx more miles."

 

Now, most people can keep track of minutes a lot better than they can keep track of miles (only the driver may see the odometer of a car, but the passengers may follow the mile-marker signs).  So, if we are going to let distance be the independent variable (often called x) of a function and to let time be the dependent variable (often called y) of the function [note: that is, y = f(x)], then we would solve D=RT for T:

                            T = D/R       [note: time depends on distance]

 

So, the amount of time that a walk takes (provided that the Rate is the same] increases as the distance increases and decreases as the distance decreases.  At our constant driving rate, it will take twice as long to get to grandma's house this year because we now live twice as far away.  And, a walk of 2 miles takes twice as long as a walk of 1 mile (IF the rate is the same).