1. A wooden bar that weighs 400 N supports two crates, one 500 N and the other 400 N. If the scale force reading in the right rope is 500 N. (a) Determine the scale force reading in the left rope. (b) Explain how this problem relates to Newton's First Law of Motion 500 N ? 400 N 500 N 400 N 2. (a) Identify significant forces that act on a cellphone at rest on a smooth (but not frictionless) flat surface? (i.e., draw a force diagram. A force diagram shows an object simply as a box, and then all forces acting on the object (box) are indicated as arrows and are labeled clearly) (b) if a brief horizontal force is exerted on the cellphone and then the force is withdrawn, we see that the cellphone slides and then comes to a stop. Does this observation go against Newton's First Law of motion? (c) Draw a force diagram to indicate all forces acting on the cellphone while it is slowing down3. In the following force diagrams, the vertical forces are not indicated but their vector sum is zero. 7m+ 3N a. Determine the net force in the horizontal direction in each case. b. which one shows an object at rest? And which one shows an object moving at constant velocity? Why? 4. You exert a horizontal force of ?00 N in order to slide a heavy crate across the floor at constant velocity. [a] How much is the force of friction between the crate and the floor in relation to the pushing force? Equal to. less than, or greater than 3'00 N? [b] Explain your response in (Me. 5. A crate sits on a frictionless surface. Sara pulls to the right with a force of 200 N while John pulls to the left with a force 150 N. Gravitational force acting on the crate is 300 N while the support force acting on the crate is 300 N. [a] What is the net force acting on the box? [b] Is the crate moving at steady velocity? Explain