# Calculating Air Resistance Work on a Thrown Ball

• BunHead
In summary, we discussed the scenario of throwing a 5kg ball with an initial velocity of 30m/s and air resistance of 25N. We found that while the ball is going up, the total force acting against the movement is (5*9.8 + 25)N and we can calculate the time and height at which the velocity will be zero. On the way down, the force is (5*9.8 - 25)N and we can calculate the time to reach the ground. The work done by air resistance is the force multiplied by the displacement, or 25N multiplied by twice the height. To calculate the kinetic energy back to the original place, we need to find the
BunHead
let's say i have a 5kg ball and i throw it up with an initial V of 30m/s with air resistance of 25, how would i find the work done by air resistance on the way up and on the way down?

Air resistance of 25? 25 what?

25N ... Thnx

While the ball is going up you have a total force of (5*9.8 + 25) N acting against the movement. So you can calculate how long it will take for the velocity to be zero and the corresponding height.
When the ball goes down, there will be a force of (5*9.8 - 25) N accelerating it. Knowing the height the ball starts on, you can calculate the time to reach ground.
edited to add:
The work done by air resistance is the force times the diplacement. Or 25N times twice the height.

Just for fun...how would we calculate the Kinectic energy back to the original place?

Find the height it will go, that distance multiplied by each force acting on it will give the work done with each force. 5*9.8 = 49N from gravity and 25N from air resistance.

Keep in mind though air resistance isn't constant, so saying 25N from air resistance doesn't really make sense.

Loozer said:
Just for fun...how would we calculate the Kinectic energy back to the original place?

Once you know the height the ball has attained and the accelerating force down (5*9.8+25)N, you can calculate the final velocity V. The kinectic energy is 5*V2

## What is air resistance and how does it affect a thrown ball?

Air resistance is a force that opposes the motion of an object through the air. It is caused by the collision of air molecules with the surface of the object. Air resistance affects a thrown ball by slowing it down and changing its trajectory.

## What factors determine the amount of air resistance on a thrown ball?

The amount of air resistance on a thrown ball depends on the surface area, shape, and speed of the ball. A larger surface area, a less streamlined shape, and a higher speed will result in greater air resistance.

## How is air resistance work calculated on a thrown ball?

Air resistance work on a thrown ball can be calculated using the equation W = Fd, where W is the work done by air resistance, F is the force of air resistance, and d is the distance the ball travels.

## What is the difference between air resistance work and kinetic energy?

Air resistance work is the energy that is lost due to the force of air resistance, while kinetic energy is the energy of motion. Air resistance work decreases the kinetic energy of a thrown ball, causing it to slow down and eventually come to a stop.

## How does the angle of release affect air resistance work on a thrown ball?

The angle of release can affect air resistance work on a thrown ball by changing the surface area and shape of the ball as it travels through the air. A higher angle of release may result in a greater amount of air resistance work due to increased surface area, while a lower angle may result in less air resistance work.

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