- #1
NoPhysicsGenius
- 58
- 0
[SOLVED] System of equations
1. Homework Statement
Use a system of equations to solve the following problems:
(a.) A boat took 1 hour 50 minutes to go 55 miles downstream and 3 hours 40 minutes to return. Find the rate of the current.
(b.) A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream. The speed of the boat is 15 mi/h greater than the speed of the current. Find the speed of the current.
(c.) A boat travels 12 miles downstream in 1.5 hours. On the return trip the boat travels the same distance upstream in 2 hours. Find the rate of the boat in still water and the rate of the current.
2. Homework Equations
distance = rate * time
3. The Attempt at a Solution
Here's a lame-brained attempt to solve problem (b) ...
[tex]d=rt[/tex]
[tex]r=r_b + r_w[/tex]
[tex]d = (r_b + r_w)t[/tex]
[tex]r_b = 15 + r_w[/tex]
[tex]d = (15 + 2r_w)t[/tex]
? ...
I can't figure out how to solve any of these. Could you at least help me to set them up correctly? Thank you.
1. Homework Statement
Use a system of equations to solve the following problems:
(a.) A boat took 1 hour 50 minutes to go 55 miles downstream and 3 hours 40 minutes to return. Find the rate of the current.
(b.) A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream. The speed of the boat is 15 mi/h greater than the speed of the current. Find the speed of the current.
(c.) A boat travels 12 miles downstream in 1.5 hours. On the return trip the boat travels the same distance upstream in 2 hours. Find the rate of the boat in still water and the rate of the current.
2. Homework Equations
distance = rate * time
3. The Attempt at a Solution
Here's a lame-brained attempt to solve problem (b) ...
[tex]d=rt[/tex]
[tex]r=r_b + r_w[/tex]
[tex]d = (r_b + r_w)t[/tex]
[tex]r_b = 15 + r_w[/tex]
[tex]d = (15 + 2r_w)t[/tex]
? ...
I can't figure out how to solve any of these. Could you at least help me to set them up correctly? Thank you.