A car travelling on a level highway runs out of gas and coasts to a stop. A 20-kg sign is suspended by two strong cables, as shown in the What forces are acting on the car and in which directions while the car is diagram. The free-body diagram is also shown, drawn to scale. Which free-body diagram is correct if the sign is replaced by one having a mass coasting? of 40 kg? Oforce of gravity [down], force of friction [forward], and normal force 40 [up] 40 sign O force of gravity [down], applied force [forward], force of friction [forward], and normal force [up] Cable 2 O force of gravity [down], force of friction [backward], and normal force [up] A stationary block is at rest on a rough inclined plane, as shown. If Fo is the force of gravity, Fi is the normal force, and Fi is the force of Oforce of gravity [down], applied force [forward], force of friction friction, which free-body diagram below is correct? [backward], and normal force [up] 4. What concept or principle best explains why the cab of a truck is often separated from the load by a steel barrier? O steel barrier cab load O O Newton's first law O the force of friction Oacceleration 40% O the normal force A toy water rocket is partially filled with water, and air is pumped in under pressure. The rocket is suspended from a taut, smooth string by means of a hollow drinking tube attached to the rocket, as shown. The rocket is free to slide along the string. If the valve is opened to let the water escape suddenly from the rocket, far out in space where there is no atmosphere, what will happen? left right taut string drinking tube 5. A small elevator weighing 1.2 x103 N is accelerating upward. The tension in the cable is 2.0 x 103 N and the frictional resistance to the motion is release 5.0 x 102 N. What is the net force acting on the elevator? valve water air under pressure O 3.7 x103 N [up] The water will move to the left and the rocket will move to the right. O 3.0 x103 N [up] The water will move to the left and the rocket will remain stationary. O2.7 x103 N [up] O Both the rocket and the water will remain at rest. O 1.3 x103 N [up] The water will move to the left and bring the rocket along with it