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sashaice [31]
3 years ago
6

A log raft is moving downstream at a speed of 3 km/h. To insure that there are no river jams a supervisor travels along the raft

on a motor boat speed of which in still water is 15 km/h. What is the length of the log raft, if it takes the supervisor 16 minutes to travel from one end of the raft to another and back?
Mathematics
1 answer:
skad [1K]3 years ago
8 0

Answer:

2000 meters

Step-by-step explanation:

When the motorboat is moving downstream, its speed relative to the ground is 18 km/h, so its speed relative to the raft is 15 km/h.

When the motorboat is moving upstream, its speed relative to the ground is 12 km/h, so its speed relative to the raft is again 15 km/h.

Converted to m/min, the relative speed is:

15 km/h × (1000 m/km) × (1 h / 60 min) = 250 m/min

It takes the motorboat 16 minutes to travel to the front of the raft and back.  Since the speed is the same in both directions, the motorboat takes 8 minutes to travel the length of the raft.

So the length of the raft is 250×8 = 2000 meters.

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Let Laura's time be x minutes.

Then we have:

x + 3x - 16 = 68

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So Sadie took 3(21) - 16 = 63-16

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3 years ago
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Answer:

1. Not possible. The slope of such a line is undefined. Its equation is x=7.

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In slope-intercept form, the equation would be useless:

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3 years ago
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