Energy Expenditure of a Kayaker
a. How much energy does the kayaker expend during a 2km paddle?
Given data: Someone paddles a kayak at a steady speed of 1.50m/s. The kayaker paddles to compensate for the drag force of 33N exerted by the water on the kayak. The mass of kayak and person combined is 60kg.
b. What is the power expended by the kayaker?
Given data: Someone paddles a kayak at a steady speed of 1.50m/s. The kayaker paddles to compensate for the drag force of 33N exerted by the water on the kayak. The mass of kayak and person combined is 60kg.
Answer:
The kayaker expends 66000J of energy during a 2km paddle. The power expended by the kayaker is 49.5W.
Energy expenditure and power calculation are essential in understanding the physical effort required for activities such as kayaking. In this scenario, we are given that a kayaker is paddling at a steady speed of 1.50m/s to compensate for the drag force of 33N exerted by the water on the kayak. The mass of the kayak and person combined is 60kg.
Calculating the Energy Expenditure:
To calculate the energy expended by the kayaker during a 2km paddle, we need to determine the work done. Work is given by the formula: Work = Force * Distance. In this case, the force is the drag force exerted by the water on the kayak, which is 33N, and the distance is 2km (2000m).
Therefore, Work = 33N * 2000m = 66000J. This means that the kayaker expends 66000J of energy during a 2km paddle.
Calculating the Power:
To find the power expended by the kayaker, we use the formula: Power = Work / Time. Since the kayaker is paddling at a steady speed, we can assume the time taken to cover 2km is the same as the time taken to cover 2km at a speed of 1.50m/s.
Time = Distance / Speed = 2000m / 1.50m/s = 1333.33s. Therefore, the power expended by the kayaker is calculated as Power = 66000J / 1333.33s = 49.5W. This indicates that the kayaker expends 49.5 watts of power during the paddling activity.
Understanding the energy expenditure and power output in physical activities can provide insights into the amount of effort required and overall performance levels. By calculating these values, individuals can better optimize their performance and training strategies.