Two students are running down the hallway towards each other. Student 1 has a mass of 107kg and is running to the right at 4.1m/s. Student 2 has a mass of 97kg and is running to the left at 7.1m/s. If they strike in an elastic collision, what is the velocity of student 2 if student 1 moves at 6.55m/s to the left after the collision?

The consumption of fossil fuels could be

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.

Adolphin emits ultrasound at 100khz and uses the timing of reflections to determine the position of objects in the water. part a what is the wavelength of this ultrasound? assume that temperature of water is 20 degrees c. answer in cm