Joe is a former basketball player who is now a work-out junkie, and especially loves to do push-ups. He was a good athlete, but not so good at science in school, especally not good in Physics. He wants you, yes you, to calculate how much work he does, in strict terms of Physics, when he does his push-ups.
Joe is exactly 2 metes tall. His center of gravity is in the middle, one meter from either end. When he places his hands to do push-ups, they are 1.5 meters from his toes. He has long arms, so when he raises himself up all the way off the floor, his center of gravity is exactly one meter off the floor (OK, that makes him built like an orangutan, give me a break, I'm trying to keep the numbers simple). How much work would he do, in Joules, of course, if he does 100 push-ups? Remember, the acceleration of gravity is 9.8 meters per second squared.
How about if you, yes you, do the calculations? It is you who is taking the course.
Where he places his hands doesn't matter. We will have to assume that his center of gravity is at floor level at the bottom of his pushups, although this cannot be strictly true.
Calculate how far he raises his body with each pushup, and multiply that by m g x 100.
Here is the problem
A typical atom has a diameter of about 1.0 X 10^-10m. What it is in inches?
How many atoms are there along a 1.0 cm line?
( I got the first part but confuse w/ the second part. how do I know how many atoms are there? Please help me)
To calculate the work done by Joe while doing push-ups, we need to determine the change in potential energy. Work is defined as the product of force and displacement, which can be written as:
Work = Force * Displacement
In this case, the force acting on Joe is his weight, which can be calculated using his mass and the acceleration due to gravity. The weight can be calculated as:
Weight = mass * gravity
In this scenario, Joe's weight acts vertically downward, while he raises himself up during the push-up. The displacement in this case is the change in height from the starting position to the highest point he reaches.
The change in potential energy can be calculated as:
Change in Potential Energy = Weight * Change in Height
Since Joe's center of gravity rises by one meter, the change in height is 1 meter.
Now, let's break down the calculations:
1. Calculate Joe's weight:
Joe's weight = mass * gravity
We don't have Joe's mass, so let's assume an average mass for an adult male, which is around 75 kilograms.
Joe's weight = 75 kg * 9.8 m/s^2 = 735 N
2. Calculate the change in potential energy:
Change in Potential Energy = Weight * Change in Height
Change in Potential Energy = 735 N * 1 m = 735 Joules (J)
Now that we have calculated the change in potential energy for a single push-up, we can calculate the total work done by Joe when performing 100 push-ups:
Total Work = Change in Potential Energy * Number of Push-ups
Total Work = 735 J * 100 = 73,500 Joules (J)
Therefore, Joe would do 73,500 Joules of work if he does 100 push-ups.