Alazy physics student is made to walk the plank. the plank is 8m above the water. if the plank is pulled out from under the student and he falls straight down, how long will it take him to hit the water?

In a bumper car arena, two cars of equal mass are heading straight toward each other. the orange one is traveling at a speed of 5 meters per second. the green one is traveling at a speed of 2 meters per second. which of the forces most affects the motion of the bumper cars after they collide? a) gravity b) friction c) the other car d) wind resistance

What are atoms of the same element with varying number of neutrons

1. jay fills a wagon with sand (about 20 kg) and pulls it with a rope 30 m along the beach. he holds the rope 25° above the horizontal. the rope exerts a 20-n tension force on the wagon. how much work does the rope do on the wagon?