Someones car will not start, so two friends help him by pushing it. the mass of the car is 800 kg. By pushing as hard as they can for 10 seconds they make the car reach a speed of 2 metres per. second. calculate the acceleration they give to the car

An atom that has fewer electrons that protons is called a positive ion.

The objects are acted upon by only one force. gravity. mass times the acceleration of gravity (-9.81meters/second squared).

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero.