Calculating the Force from Power Loss at 75.0 Km/hr

In summary, the conversation discusses testing a new car in a wind-tunnel to determine the resistance of the road and wind at a speed of 75.0 Km/hr. It is found that 63.0% of the total output power of the engine is used to overcome this resistance. With an output power of 69.00 HP, the force of this resistance is being calculated in Newtons. However, the calculations provided are incomplete and it is suggested to check the units used throughout the formula for power in order to find the correct answer.
  • #1
jacksondwrd
2
0
You are testing a new car in a wind-tunnel for road and wind resistance. At a speed of 75.0 Km/hr you have found that 63.0 % of the total output power of an automobile engine is used in overcoming the resistance of the road and wind against the movement of the car. If the output power of a particular car engine is 69.00 HP, what is this resistance (ie. what is the force)? Give your answer in Newtons. (Take one HP as 746 Watts.


so i was like calcualting it like this

69HP=51474
and 60% of 51474 is 32428.62

then i did the formula of the power

power=forcexdistance/time

and got that answer but it is wrong

can anyone explain to me what i did wrong here
 
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  • #2
Well, you stopped showing your calculations after figuring the power used to overcome wind resistance. I don't know what you did to calculate the force, but did you check the units of your calculations all the way thru?
 
  • #3
As SteamKing mentione, you didn't mention what units you used for the terms in power = force x speed. It would help us to help you if you showed more of your work.
 

Related to Calculating the Force from Power Loss at 75.0 Km/hr

1. How do you calculate the force from power loss at 75.0 km/hr?

The formula for calculating force from power loss is force = power loss / velocity. In this case, the velocity is 75.0 km/hr.

2. What is power loss?

Power loss is the amount of energy that is lost during the transfer of power from one system to another. In this case, it refers to the energy lost due to air resistance at a speed of 75.0 km/hr.

3. Why is it important to calculate the force from power loss?

Calculating the force from power loss can help determine the amount of energy needed to overcome air resistance at a certain speed. This information can be useful for designing more efficient vehicles or predicting fuel consumption.

4. What units are used to measure force and power loss?

Force is typically measured in Newtons (N), while power loss is measured in Watts (W). However, in some cases, other units such as horsepower (hp) may be used for power loss.

5. Are there any other factors that can affect the force from power loss at 75.0 km/hr?

Yes, other factors such as the shape and size of the object, air density, and surface roughness can also affect the force from power loss at 75.0 km/hr. These factors should be taken into consideration when calculating the force from power loss.

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