SOLUTION: You and a friend are 400 m away from school, walking together toward home at a speed of 1.9 m/s. Suddenly, you remember that you remember that you need to bring your physics binder

Question 933777: You and a friend are 400 m away from school, walking together toward home at a speed of 1.9 m/s. Suddenly, you remember that you remember that you need to bring your physics binder! You turn around and run (with a speed of 4.2 m/s) back to school, while you friend continues to walk. Then, you run back toward your friend to catch back up. How long are you running (total) before you catch back up with your friend?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
You run back to school at 4.2m/s
distance = 400 m
time taken by you to reach school = 400/4.2= 95.2 seconds
during that time your friend is walking at 1.9 m/s
so he has walked ahead 1.9*95.2=180.9 m
when you are at school he is 400 + 181 = 581 m ahead of you
catch time = catchup distance /catch up rate
581/(4.2-19)
581/2.3= 252.6 sec
so you run 95.2 sec + 252.6 sec
=

RELATED QUESTIONS
you are walking from your physics class at a speed of 1.0 m/s. your friend leaves two... (answered by richwmiller)

You and a friend are 4.5kilometers away from each other. Walking toward each other, the... (answered by lwsshak3)

Rocco and Biff are two koala bears frolicking in a meadow. Suddenly, a tasty clump of... (answered by math_tutor2020)

Carlos lives 500 meters away from his friend�s home. He starts to sprint to his friend�s (answered by macston)

You and your friend live 12 miles away from each other. You leave home at the same time... (answered by ankor@dixie-net.com)

Billy leaves home walking to school at 1.7 m/s. His sister Sally is running a bit late... (answered by lwsshak3)

You and your friend live 12 miles apart. You leave home at the same time and travel... (answered by jorel1380)

A person of height 1.68 m is walking away from a lamp-post at 1.5 m/s. The light on the... (answered by rothauserc)

5. A comet is flying at a speed of 400 m/s when it reaches the earth�s orbit and starts... (answered by Alan3354)