How much time does it take a person to walk 12 km north at a velocity of 6.5 km/h

What happens to light waves from a star as the star moves away from earth?

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

While the change in blank will remain the same during a collision, the force needed to bring an object to a stop can be blank if the time if collision is blank