Simple question on Ratio of Kinetic to rest energy

MillerGenuine

1. The problem statement, all variables and given/known data

A pitcher can throw a baseball at 44 m/s. what is the ratio of kinetic energy to the rest energy E=mc^2. (can you use k=1/2mv^2 ?)

2. Relevant equations

rest energy=mc^2
K=gamma*mc^2 - mc^2
k=1/2mv^2

3. The attempt at a solution
Im just not sure how to go about this problem. It seems i can use k=1/2mv^2 because the velocity is well below c. From there i would take me kinetic energy and divide it by the rest enregy to get the ratio..??

Related Introductory Physics Homework News on Phys.org

berkeman

Mentor
1. The problem statement, all variables and given/known data

A pitcher can throw a baseball at 44 m/s. what is the ratio of kinetic energy to the rest energy E=mc^2. (can you use k=1/2mv^2 ?)

2. Relevant equations

rest energy=mc^2
K=gamma*mc^2 - mc^2
k=1/2mv^2

3. The attempt at a solution
Im just not sure how to go about this problem. It seems i can use k=1/2mv^2 because the velocity is well below c. From there i would take me kinetic energy and divide it by the rest enregy to get the ratio..??
Yep. They just want to show how huge the rest energy is...

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving