# Average speed of a boat

1. Jan 31, 2009

### Makaroon

1. The problem statement, all variables and given/known data
A boat moves 15.0 km across a lake in 30.0 min. What was the average speed of the boat in kilometers per hour?

2. Relevant equations
average speed: d/t

3. The attempt at a solution
ok since it is asking kilometers per hour that is the part tha confuses me.
i mean i believe that it is 15.0 km/30.0
but it is asking for hour...
sooo that where i get lost.

2. Jan 31, 2009

### LowlyPion

That's what it did in 30 min.

How much would it do in an hour.

3. Jan 31, 2009

### Makaroon

oh so then i multiply that times 2?

or would i do 15.0/60?

4. Jan 31, 2009

### Makaroon

ok no..that doesn't make sense :S

5. Jan 31, 2009

### Hannisch

If it goes x km in thirty minutes and keeps the same speed, wouldn't it go the same distance in the next thirty minutes?

6. Jan 31, 2009

### Makaroon

ooh so then its the same..

7. Jan 31, 2009

### Nabeshin

Your 15km/30 is lacking one thing: Units on the 30. The 30 is in minutes, so this division would give you km/minute.

8. Jan 31, 2009

### Makaroon

hm, but it is asking for kilometers per hour.

gosh sorry i'm soo ugh for this.

9. Jan 31, 2009

### Hannisch

30 min is ½hour, right?

It goes 15km in ½hour - how much in 1 whole hour?

10. Jan 31, 2009

### Makaroon

oh so then it is 30km/h?

11. Jan 31, 2009

### Hannisch

Yep, that's it.

12. Jan 31, 2009

### Makaroon

wow! thank you so much!
i truly appreciate it!