Skip to main content
Ch. 6 - Applications of Integration
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 6, Problem 6.1.65a

Bike race Theo and Sasha start at the same place on a straight road, riding bikes with the following velocities (measured in mi/hr). Assume t is measured in hours.
Theo: vT(t)=10, for t≥0
Sasha: vS(t)=15t, for 0≤t≤1, and vS(t)=15, for t>1


a. Graph the velocity function for both riders. 

Verified step by step guidance
1
Identify the velocity functions for both riders: Theo's velocity is constant, given by \(v_T(t) = 10\) for \(t \geq 0\), and Sasha's velocity is piecewise, given by \(v_S(t) = 15t\) for \(0 \leq t \leq 1\) and \(v_S(t) = 15\) for \(t > 1\).
Set up the time axis \(t\) starting from 0 and extending beyond 1 hour to capture both parts of Sasha's velocity function.
For Theo's velocity, draw a horizontal line at \(v = 10\) since his velocity is constant for all \(t \geq 0\).
For Sasha's velocity, first draw a line starting at the origin \((0,0)\) and increasing linearly to the point \((1, 15)\) because \(v_S(t) = 15t\) is a linear function on \(0 \leq t \leq 1\).
Then, for \(t > 1\), draw a horizontal line at \(v = 15\) to represent Sasha's constant velocity after 1 hour.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
7m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Velocity as a Function of Time

Velocity describes the rate of change of position with respect to time. In this problem, velocity functions vT(t) and vS(t) give the instantaneous speed of Theo and Sasha at any time t, which is essential for plotting their motion on a graph.
Recommended video:
10:17
Using The Velocity Function

Piecewise Functions

A piecewise function is defined by different expressions over different intervals of the domain. Sasha's velocity vS(t) changes definition at t=1, requiring careful graphing of each segment separately to accurately represent her velocity over time.
Recommended video:
05:36
Piecewise Functions

Graphing Functions

Graphing involves plotting points and connecting them to visualize how a function behaves over its domain. Understanding how to graph constant and linear velocity functions helps illustrate the riders' speeds and compare their motion visually.
Recommended video:
5:53
Graph of Sine and Cosine Function