Calculating Truck Power Requirements for Constant Velocity Travel

In summary, the power required to drive the truck at different speeds can be calculated using the formula P = Fv, where P is power, F is force and v is velocity. At 30.0 km/h, the total power required is 21.7 kW or 29.0 hp, while at 120.0 km/h, the total power required is 32.2 kW or 43.1 hp. The force of rolling friction is 65% of the total resisting force, and the force of air resistance is proportional to the square of the speed.
  • #1
mohd22
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A truck engine transmits 28.0 kW (37.5 hp) to the driving wheels when the truck is traveling at a constant velocity of magnitude 60.0 km/h( 37.3 mi/h) on a level road.



1.Assume that 65% of the resisting force is due to rolling friction and the remainder is due to air resistance. If the force of rolling friction is independent of speed, and the force of air resistance is proportional to the square of the speed, what power will drive the truck at 30.0 km/h? Give your answer in kilowatts
2.Assume that 65% of the resisting force is due to rolling friction and the remainder is due to air resistance. If the force of rolling friction is independent of speed, and the force of air resistance is proportional to the square of the speed, what power will drive the truck at 30.0 km/h? Give your answer in horsepower.
3.Assume that 65% of the resisting force is due to rolling friction and the remainder is due to air resistance. If the force of rolling friction is independent of speed, and the force of air resistance is proportional to the square of the speed, what power will drive the truck at 120.0 km/h? Give your answer in kilowatts
4.Assume that 65% of the resisting force is due to rolling friction and the remainder is due to air resistance. If the force of rolling friction is independent of speed, and the force of air resistance is proportional to the square of the speed, what power will drive the truck at 120.0 km/h? Give your answer in horsepower.
 
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  • #2


1. To calculate the power required to drive the truck at 30.0 km/h, we can use the formula P = Fv, where P is power, F is force and v is velocity. The total resisting force is 65% of 28.0 kW, or 18.2 kW. The remaining 35% is due to air resistance, which is proportional to the square of the speed. This means that at 30.0 km/h, the air resistance force is (30.0/60.0)^2 * 0.35 * 28.0 kW = 3.5 kW. Therefore, the total power required to drive the truck at 30.0 km/h is 18.2 kW + 3.5 kW = 21.7 kW.

2. To convert from kilowatts to horsepower, we can use the conversion factor 1 kW = 1.34 hp. Therefore, the power required to drive the truck at 30.0 km/h is 21.7 kW * 1.34 = 29.0 hp.

3. To calculate the power required to drive the truck at 120.0 km/h, we can use the same formula as before. The total resisting force is still 65% of 28.0 kW, or 18.2 kW. However, the air resistance force is now (120.0/60.0)^2 * 0.35 * 28.0 kW = 14.0 kW. Therefore, the total power required to drive the truck at 120.0 km/h is 18.2 kW + 14.0 kW = 32.2 kW.

4. Converting from kilowatts to horsepower, we get 32.2 kW * 1.34 = 43.1 hp. Therefore, the power required to drive the truck at 120.0 km/h is 43.1 hp.
 

What is automotive power?

Automotive power refers to the energy or force that is necessary to make a vehicle move and function properly. It is typically measured in horsepower (hp) or kilowatts (kW) and is generated by the engine of the vehicle.

How is automotive power generated?

Automotive power is generated by the engine of a vehicle through the process of combustion. This involves burning fuel, typically gasoline or diesel, in a controlled explosion to produce energy that powers the engine and ultimately moves the vehicle.

What factors affect automotive power?

There are several factors that can affect automotive power, including the type of fuel used, the size and design of the engine, and the efficiency of the combustion process. Other factors such as altitude, temperature, and air density can also impact the power output of a vehicle.

What is the difference between horsepower and kilowatts?

Horsepower and kilowatts are both units of measurement for automotive power. Horsepower is a unit of measurement traditionally used in the United States and is a measure of the power needed to lift 550 pounds one foot in one second. Kilowatts are a more modern unit of measurement used globally and are a measure of electrical power equal to 1,000 watts.

How can automotive power be increased?

There are various ways to increase automotive power, including improving the engine's design for more efficient combustion, using higher quality fuel, and adding components such as turbochargers or superchargers. Regular maintenance and tuning of the engine can also help to optimize its performance and increase power output.

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