Work and Kinetic Energy of baseball

In summary, the conversation discusses the calculation of foot pounds of work required to throw a baseball at 90 mph. The correct equation is W=(change)KE, with KE=1/2mv^2. The issue at hand is incorrect unit conversions, specifically with converting miles per hour to feet per second and pounds to slugs. After realizing the mistake of not converting the weight of the ball to its mass using gravitational acceleration, the correct answer of 85.1 ft-lbs is obtained.
  • #1
saraleigh117
2
0
How many foot pounds of work does it take to throw a baseball 90 mph? A baseball weighs 5 oz, or 0.3125 lb.

The only equation I can find is W= (change) KE, where KE=1/2mv^2

When I try plugging in the data given I'm not getting the correct answer. I don't know if I'm doing incorrect unit conversions or what. This is actually in my calculus book physics but this seemed like the more appropriate place to post the question. By the way, the answer in the book is 85.1 ft-lbs. Please help me. I'm dyin' over here.
 
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  • #2
You have the right equation, so you must be doing your conversions incorrectly, which is a little tough in the USA units when mass comes into play. You must first convert miles/hr to ft/sec, and pounds to slugs per m=W/g.
 
  • #3
Post your calculations.
 
  • #4
Nevermind, I've got it. I didn't convert the weight of the ball to the mass of the ball using the gravitational acceleration. Thanks.
 

What is the work and kinetic energy of a baseball?

The work and kinetic energy of a baseball refers to the amount of energy required to move the baseball from one point to another and the energy that the baseball has while in motion, respectively. It takes work to move the baseball, which is then converted into kinetic energy as the baseball travels through the air.

How is the work and kinetic energy of a baseball calculated?

The work and kinetic energy of a baseball can be calculated using the formulas W = F x d and KE = 1/2 x m x v^2, respectively. W represents work, F represents force, d represents distance, KE represents kinetic energy, m represents mass, and v represents velocity.

What factors affect the work and kinetic energy of a baseball?

The work and kinetic energy of a baseball can be affected by several factors, including the force used to throw the baseball, the distance the baseball travels, the mass of the baseball, and the velocity at which the baseball is thrown. Other factors such as air resistance and gravity can also affect the work and kinetic energy of the baseball.

Why is understanding the work and kinetic energy of a baseball important?

Understanding the work and kinetic energy of a baseball is important for several reasons. It helps us understand the physics behind the sport of baseball and how different factors can affect the movement of the baseball. It also allows us to make predictions about the trajectory and speed of the baseball, which can be useful for players and coaches.

How do the work and kinetic energy of a baseball relate to each other?

The work and kinetic energy of a baseball are directly related to each other. As work is done to move the baseball, its kinetic energy increases. The more work that is done, the more kinetic energy the baseball will have. This relationship is described by the work-energy theorem, which states that the net work done on an object is equal to its change in kinetic energy.

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