Question

HELP:Sarah, who is 19 feet away from Justin, has a ball in her hand. Sarah throws the ball away from Justin at a speed of 5 feet per second. It takes the ball 4 seconds to reach a third friend, Brandon. When the ball reaches Brandon, how far away is it from Justin?

Answer 1

Answer:

Justin is 1 feet far away from Brandon

Step-by-step explanation:

As shown in the diagram, we let the distance between Justin and Brandon be x

$Speed = \frac{distance}{time}$

from the question

the total time taken by the ball to reach Brandson=4s

Also the total distance is travelled by the ball=19+x

while the average speed=5ft/s

By substitution we obtain

$5 = \frac{19 + x}{4}$

$\implies4 \times 5 = 19 + x$

$\implies20=19 + x$

$\implies20 - 19 = x$

x=1 feet