A kayaker paddles with a power output of 490 W to maintain a steady speed of 1.50 m/s. What is the resistive force exerted by the water on the kayak?

2 Answers
Dec 7, 2015

Answer:

#326.6"N"#

Explanation:

Using dimensional analysis:

Watts = #"N"."m.s"^(-1)#

#:.("N".cancel("m.s"^(-1)))/(cancel("m.s"^(-1)))="N"#

#:.F=490/1.5=326.6"N"#

Dec 7, 2015

Answer:

I found #163.3N# but check my method (whether it makes sense or not!).

Explanation:

Have a look:
enter image source here
I considered the fact that the kayaker has to put energy to push the kayak and to overcome water resistance...I think.