Need hel plz 60 POINTS
4. A waiter carries a tray of food across a room. How much work was done on the tray?How do you know?

5. What is the equation for total mechanical energy?

6. Which of the following objects has more kinetic energy?

Explain your answer!!!
A 15 kg ball rolling north at 15 m/s

OR

A 15 kg ball rolling backwards at 7 m/s

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. 

Answermuch larger;

Two cars collide, lock bumpers and move together after the collision.this collision is known as perfectly inelastic collision.