A cart rolling down an incline for 2.0 seconds has a beginning speed of 3.0m/s, what Is the final speed or volocity?

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?

The average time that it takes for the car to travel the first 0.25m is s. the average time to travel just between 0.25 m and 0.50 m is s. given the time taken to travel the second 0.25 m section, the velocity would be m/s.