Ablue train of mass 50 kg moves at 4 m/s toward a green train of 30 kg initially at rest. the trains collide. after the collision the green train moves with a speed of 3 m/s. what is the final momentum of the blue and green train combined?
a. 90 kgm/s
b. 110 kgm/s
c. 50 kgm/s
d. 200 kgm/s

Waves are used in many practical applications to support work, entertainment, and health. one example is the use of ultrasound imaging to safely track the development of a growing fetus. what is a specific example of a practical application of waves in medicine, entertainment, safety, or other fields? provide a brief explanation of how the properties of waves are useful to that application.

Which body is in equilibrium? (1) a satellite orbiting earth in a circular orbit (2) a ball falling freely toward the surface of earth (3) a car moving with a constant speed along a straight, level road (4) a projectile at the highest point in its trajectory

Atruck with 34-in.-diameter wheels is traveling at 55 mi/h. find the angular speed of the wheels in rad/min, *hint convert miles to inches & hours to minutes: