Multiple Choice Questions

Do the blocks ever have the same acceleration? The position of two blocks at successive 0.20-second time intervals are represented by numbered squares in the figure below. The blocks are moving toward the right. 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 Do the blocks ever have the same acceleration? Do the blocks ever have the same speed? Do the blocks ever have the same position?

When is the acceleration most negative? (A) R to T (B) T to V (C) V (D) X (E) X to Z

An object starts from rest and undergoes a positive, constant acceleration for ten seconds. It then continues on with a constant velocity. Which of the following graphs correctly describes this situation?

Which sentence is the best interpretation of the graph? (A) The object is moving with a constant acceleration (B) The object is moving with a uniformly decreasing acceleration. (C) The object is moving with a uniformly increasing velocity. (D) The object is moving at a constant velocity. (E) The object does not move.

Next questions refer to collisions between a car and a truck Next questions refer to collisions between a car and a truck. Choose the one answer from the possibilities A though J that best describes the forces between the car and the truck. Ftruck_on_car >Fcar_on_truck B. Ftruck_on_car <Fcar_on_truck C. Neither exerts a force on the other; the car gets smashed simply because it is in the way of the truck. D. The truck exerts a force on the car but the car doesn't exert a force on the truck. E. Ftruck_on_car =Fcar_on_truck . F. Not enough information is given to pick one of the answers above. J. None of the answers above describes the situation correctly. If Vtruck = Vcar If Vtruck << Vcar If Vtruck = 0

Problems

Read. Read the problem at least three times. Visualize. Try to visualize the situation described in the problem Picture and translate. Draw a real picture of the problem situation. Do not forget the coordinate axis. Simplify. Think of what simplifications you can make Represent physically. Sketch a motion diagram or a free-body diagram. Represent mathematically. Construct a mathematical representation of the situation. Solve. Use mathematical relationships from part 6 to solve for the unknown quantity (quantities). Make sure that you use consistent units. Evaluate the result. Is the number reasonable? Are the units appropriate? Does the result make sense in limiting cases?

V1 V2 D X Find the position and time when the two bikes meet