# Calculating Average Speed of Tennis Ball

• Alucard2487
In summary, the problem involves calculating the average speed of a tennis ball at two different points in time. The distance between the two points can be approximated as a straight line, and the average velocity vector can be used to determine the average speed.

## Homework Statement

At a time 0.22 seconds after it has been hit by a tennis racket, a tennis ball is located at (6, 8, 0)  m, relative to an origin in one corner of a tennis court. At a time 0.26 seconds after being hit, the ball is located at (6.52, 8.16, 5.88)  m. Calculate the following results, and include correct units:

(b) What is the average speed of the tennis ball?

## The Attempt at a Solution

I had to calculate the average velocity. I got (13, 4, -3) m/s and I have the unit vector (.934, .287, -.215). i know that vavg = deltad/deltat. The problem is that the speed is a scalar and that confuses me.

Speed = Distance/Time.

You are given the time. Calculate the distance between the two points.

Given such a short time interval we can safely approximate the path of the ball to straight line by ignoring the effect of gravity. For a particle moving in a straight line which doesn't change its direction of motion the magnitude of the average velocity vector gives the average speed.

## 1. How do you calculate the average speed of a tennis ball?

To calculate the average speed of a tennis ball, you must first measure the distance the ball travels. Then, using a stopwatch or timing device, you should record the time it takes for the ball to travel that distance. Finally, divide the distance by the time to obtain the average speed in units of distance per time.

## 2. What is the standard unit of measurement for average speed in tennis?

The standard unit of measurement for average speed in tennis is miles per hour (mph). However, some countries may use kilometers per hour (km/h) or meters per second (m/s).

## 3. Can you calculate the average speed of a tennis ball without using a radar gun?

Yes, it is possible to calculate the average speed of a tennis ball without using a radar gun. This can be done by measuring the distance the ball travels and the time it takes to travel that distance. However, using a radar gun is the most accurate and reliable method.

## 4. Does the type of surface affect the average speed of a tennis ball?

Yes, the type of surface can significantly affect the average speed of a tennis ball. Generally, faster surfaces such as hard courts or grass courts will result in a higher average speed compared to slower surfaces like clay courts.

## 5. What is the average speed of a professional tennis player's serve?

The average speed of a professional tennis player's serve can vary depending on the player's skill level and the type of surface. However, it is estimated to be around 120-130 mph for male players and 100-110 mph for female players.