A bicyclist pedals along a straight road with velocity, v, given in the figure below. She starts 7 miles from a lake; positive velocities take her away from the lake and negative velocities take her toward the lake.

http://www.webassign.net/hgmcalc/5-3-26fig.gif

When is the cyclist farthest from the lake?
t = 1 hours (i got this part)

Approximately how far away is she at this time? Give a best estimate. (Round your answer to the nearest whole number.)

miles

Question

A bicyclist pedals along a straight road with velocity, v, given in the figure below. She starts 7 miles from a lake; positive velocities take her away from the lake and negative velocities take her toward the lake.

http://www.webassign.net/hgmcalc/5-3-26fig.gif

When is the cyclist farthest from the lake?
t =  1  hours (i got this part)

Approximately how far away is she at this time? Give a best estimate. (Round your answer to the nearest whole number.)
  

 miles

noelgreco · Answer

When she starts off, she's going toward the lake (v<0).

Her actual displacement from the starting point is the area between the graph and the x-axis with areas below the axis negative (closer to the lake).

Each division on the x-axis is 1/6 hr.  You have to estimate the area in each interval.

anonymous · Answer

yeah I know that my estimate was 77 miles and i was wrong. what would your estimate be?

noelgreco · Answer

I get 18.

77 is not reasonable because even if she pedaled at 30 mph for a whole hour she'd only go 30 miles.

Each grid square represents 10/6 miles.