Question

China and the United States are playing each other in the championship match of the 1999 Women's World Cup soccer tournament. Brandi Chastain of the U.S. team is about to take a penalty kick against the Chinese team's goalkeeper, Gao Hong. Chastain will kick the ball from 18 yards away from the goal at 120 miles per hour. How many seconds does the goalkeeper have to react, dive, and reach the ball before it crosses the goal line

Answer 1

Answer:

The goalkeeper has 0.306 seconds to react, dive, and reach the ball before it crosses the goal line.

Step-by-step explanation:

We use the following relation to solve this question:

$v = \frac{d}{t}$

In which v is the velocity, d is the distance, and t is the time.

Chastain will kick the ball from 18 yards away from the goal at 120 miles per hour.

Since the velocity is in miles per hour, the distance has to be in yards.

Each yard has 0.000568182 miles, so the ball will be kicked from 18*0.000568182 = 0.0102 miles.

This means that $v = 120, d = 0.0102$

How many seconds does the goalkeeper have to react, dive, and reach the ball before it crosses the goal line?

We have to find t, first in hours. So

$v = \frac{d}{t}$

$120 = \frac{0.0102}{t}$

$120t = 0.0102$

$t = \frac{0.0102}{120}$

$t = 0.000085$

An hour has 3600 seconds. So

3600*0.000085 = 0.306.

The goalkeeper has 0.306 seconds to react, dive, and reach the ball before it crosses the goal line.