Question

A small 20-kg canoe is floating downriver at a speed of 2 m/s. What is the canoe’s kinetic energy? A. 40 J B. 80 J C. 18 J

Answer 1

Answer:

A. 40 J

Explanation:

Kinetic energy is:

KE = ½ mv²

where m is mass and v is velocity.

Given m = 20 kg and v = 2 m/s:

KE = ½ (20 kg) (2 m/s)²

KE = 40 J

Answer 2

A small 20-kg canoe is floating downriver at a speed of 2 m/s. 40 J is the canoe’s kinetic energy.

Answer: Option A

Explanation:

The given canoe has the mass and is being given to move at a speed. Therefore the kinetic energy of the canoe can be calculated using the following method,

Given that mass of the canoe = 20 kg and its speed =1 m/s

As we know that the Kinetic energy has the formula,

$\text {Kinetic energy}=\frac{1}{2} \boldsymbol{m} \boldsymbol{v}^{2}$

Therefore, substituting the value into the equation, we get,  

$K . E .=\frac{1}{2} \times 20 \times 2^{2}$ = 40 J