微积分I(标准路径) · 免费预览

§4.1 Determining distance traveled from velocity

如果我们知道运动物体在给定区间上每一点的速度,我们能否确定物体在该时间段内走过的距离?

1. Introduction

Introduction

2. Area under the graph of the velocity function

Area under the graph of the velocity function

3. Two approaches: area and antidifferentiation

Two approaches: area and antidifferentiation

4. When velocity is negative

When velocity is negative

5. Area under constant velocity

A walker strolls at a constant v(t)=3v(t) = 3 miles per hour for two hours. The distance traveled equals the area under the velocity line on [0,2][0,2], which is

6. Ball displacement over a half second

A tossed ball has v(t)=32−32tv(t) = 32 - 32t feet per second and antiderivative s(t)=32t−16t2s(t) = 32t - 16t^2 with s(0)=0s(0) = 0. The change in position s(1)−s(12)s(1) - s(\frac{1}{2}) equals

7. Zero net change over the full flight

For the same ball, s(2)−s(0)=0s(2) - s(0) = 0. The correct interpretation is

8. Refining the rectangle estimate

A four-rectangle estimate with width 0.50.5 gave 3.753.75 miles for the walker's trip. To improve the estimate, the natural next step and its result are

9. Undoing the power rule for position

With v(t)=0.5t3−1.5t2+1.5t+1.5v(t) = 0.5t^3 - 1.5t^2 + 1.5t + 1.5, the position function satisfying s′=vs' = v is

10. An antiderivative meeting an initial condition

For the ball with v(t)=32−32tv(t) = 32 - 32t, the antiderivative ss satisfying s(0)=0s(0) = 0 is

11. Reading motion from the velocity sign

A velocity graph is positive on 0<t<10 \lt t \lt 1, negative on 1<t<41 \lt t \lt 4, and positive again on 4<t<84 \lt t \lt 8. The position function

12. Two different totals from one trip

An object's velocity bounds areas of 11 on [0,1][0,1], 44 on [1,4][1,4], and 88 on [4,8][4,8], with the middle stretch below the axis. The total change in position and total distance traveled are

13. Shape of the position graph

Plotting exact positions at integer times from velocity data, the position graph

14. Four rectangle estimate

With velocity data v(0)=1.5v(0) = 1.5, v(0.5)=1.9375v(0.5) = 1.9375, v(1.0)=2v(1.0) = 2, v(1.5)=2.0625v(1.5) = 2.0625 and rectangle width 0.50.5 hours, compute the left endpoint estimate of distance on [0,2][0,2], rounded to two decimals.

15. Position change from an antiderivative

With v(t)=0.5t3−1.5t2+1.5t+1.5v(t) = 0.5t^3 - 1.5t^2 + 1.5t + 1.5 and antiderivative s(t)=18t4−12t3+34t2+32ts(t) = \frac{1}{8}t^4 - \frac{1}{2}t^3 + \frac{3}{4}t^2 + \frac{3}{2}t, compute s(2)−s(0)s(2) - s(0).

16. Triangle area under a falling velocity

Between t=12t = \frac{1}{2} and t=1t = 1 the ball's velocity line drops from 1616 to 00 feet per second. Compute the exact area of the enclosed region.

17. One trip, two readings

An object's velocity bounds two triangular regions of area 11 each on [0,1][0,1] and [1,2][1,2], with the second below the axis, and s(0)=1s(0) = 1. The total distance, net change, and position at t=2t = 2 are

18. Full first second of flight

Using s(t)=32t−16t2s(t) = 32t - 16t^2, compute s(1)−s(0)s(1) - s(0), the vertical distance traveled on [0,1][0,1].

19. Rising where velocity is positive

An object's position function is increasing on exactly those intervals where its velocity is positive.

进入交互式练习

免费注册 · 即时批改 · 自动安排间隔复习。

免费开始这门课