Race car 20 meters east, turned around, and went 40 meters west. His car was 20 meters from the starting line. This took 5 seconds. What is the car's average velocity?

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

Your science teacher brings in a speaker to talk to your class about climate change. during the session, students ask a few questions. which questions are related to the current evidence on climate change