Question

a small 24 kilogram canoe is floating downriver at a speed of 3 m/s.what is the canoe's kinetic energy .
{~please help fast ~}

Answer 1

That all depends who's measuring it.

... If one Physics student is standing on the riverbank, watching the canoe float by, he will measure the canoe's kinetic energy and say it's  108 Joules.

... If another Physics student is sitting on another boat, floating on the same river and watching the same canoe, she will say that the canoe has zero kinetic energy.

Both of them are correct. 

Answer 2

Explanation :

Mass of the canoe, m = 24 kg

Speed of the canoe, v = 3 m/s

Kinetic energy is said to be possessed due to the motion of the object and it is given as :

$E_k=\dfrac{1}{2}mv^2$

v is the velocity of the canoe.

$E_k=\dfrac{1}{2}\times 24\ kg\times (3\ m/s)^2$

$E_k=108\ J$

So, the kinetic energy of the canoe is 108 J

Hence, this is the required solution.