Average Power delivered to Engine

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SUMMARY

The average power delivered by a 1000 kg car accelerating uniformly to 15 m/s in ten seconds, accounting for a constant air resistance of 300 N, is calculated to be 13,500 W. The formula for average power is defined as work divided by time, where work is the product of force and displacement. The force exerted by the car is determined using the equation force = mass x acceleration, leading to the correct calculation of power when factoring in displacement and air resistance.

PREREQUISITES
  • Understanding of Newton's Second Law of Motion
  • Familiarity with the concepts of work and power in physics
  • Basic knowledge of kinematics, particularly uniform acceleration
  • Ability to perform calculations involving forces and resistances
NEXT STEPS
  • Study the principles of Newton's Second Law of Motion
  • Learn about calculating work done against resistive forces
  • Explore the concept of average power in mechanical systems
  • Investigate kinematic equations for uniformly accelerated motion
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and dynamics, as well as educators seeking to explain concepts of power and force in real-world applications.

davidatwayne
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Homework Statement


A 1000 kg car, starting from rest, accelerates uniformly to 15 m/s in ten seconds. Assume air resistance is constant at 300N. What is the average power delivered by the engine?

Answers
a. 13500 W
b.18000 W
c. 23000 W
d. 27000 W

Homework Equations


Average power = work/time
work = force(x) where x is magnitude of displacement.
force= mass x acceleration


The Attempt at a Solution



the force is equal to 1000 kg x 15 m/s = 15000

I don't know how to factor in air resistance, or arrive at a final answer. The answer is A...
 
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explain how you got the force of the car again...
 
force = mass times acceleration
1000 x 15= 15000
 
what is the units of the 15 value though
 
ok... i think i got it... after getting the correct force (and units) times the displacement of x, (1800 * 75)/10... gives the correct answer.

thanks.
 

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