Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A book is at rest on a desk. Which statement is true? a. The normal force balances the force of gravity. b. The normal force and gravity both point downwards. c. Gravity is the only force acting on the book. d. The normal force is the only force acting on the book. 2. Which statement is true about Newton's Laws of Motion? a. They consist of three separate statements. b. They explain how and why objects move or stay at rest. c. They describe the forces that objects exert on each other. d. all of the above 3. A soccer ball is rolling along the ground at 5.0 mfs. After some time, it is observed to come to a stop. Which of the following is true? a. Motion at a constant speed needs a net force to maintain the motion. b. Gravity exerts a force that stops the ball. 0. Friction between the ball and the ground exerts a force to stop the ball. d. Newton's First Law says that if the external net force on an object is zero, it cannot continue moving. 4. Inertia is the property of matter a. that causes an object to resist any changes to its state of motion. b. that causes an object at rest to stay at rest unless a net force acts on it. c. that causes an object in motion to stay at a constant velocity unless a net force acts on it. (1. all of these. 5. What is the value of 1 newton as a unit of force? a. 1 kg mats2 13- 1 kg rats2 0. 1 kg mu's d- lkgms2 . An airplane ying east experiences forces of lift, drag, weight and thrust as shown in the FBD. What is the net force acting on the airplane? .. 3:20000 FN=SUDUN F" = 0000 N a. 7000N[E] b. 3000N[E] c. 3000N[W] d. 3000N[UP] . A car is pulling west on a trailer with a force of 1500 N. According to Newton's Third Law, What other force must be acting? a. a force on the trailer of 1500 N [E] b. a force on the trailer of 1500 N [W] e. a force on the car of 1500 N [W] d. a force on the car of 1500 N [E] Milos says, \"I weigh 500 N, and therefore, exert a force of 500 N on the ground when I stand on it. Newton's Third Law says that the Earth exerts a normal force of 500 N [up] on me.\" Which statement is true? a. Milos is correct. b. The reaction force is the force of gravity exerted by the Earth on Milos. c. The reaction force is the force of gravity exerted by Miles on the Earth. d. The ground is an inanimate object, and cannot exert a force. The force of kinetic friction between a sled and the snow on a level trail is 25.0 N. The sled is being pulled at a constant speed by rope is attached to the front of the sled. The force is exerted on the rope at an angle of 320 above the horizontal. In order to keep the sled moving at a constant speed, the applied force on the rope a must be more than 25.0 N. b. must be exactly 25.0 N. c. must be less than 25.0 N but not 0 N. d. must be 0 N. 10. A mass of 5.0 kg is placed on a frictionless table. A massless string is attached to the mass, and run over a system? frictionless pulley to a hanging mass of 8.0 kg. If the hanging mass is released, what is the acceleration of the a. 0 m/s2 b. 3.8 m/s2 C. 6.0 m/s2 d. 9.8 m/s211. A tugboat is attached to a barge of mass 5100 kg with cable #1. A second barge with a mass of 12 000 kg is attached to the rst barge with cable #2. The tugboat pulls the two barges with an acceleration of 0.030 m/s2. What are the tensions in cables #1 and #2? a. cable #1: 510 N; cable #2: 360 N b. cable #1: 360 N; cable #2: 510 N 0. cable #1: 360 N; cable #2: 360 N d. cable #1: 510 N; cable #2: 510N 12. A ferry is being pushed with a force of 40.0 N [W] by its engines. It enters a strong current from the north, which exerts a force of 30.0 N on the ferry. What is the net force acting on the ferry a. 70.0 N [W 36.9 E] b. 50.0 N [W 369 E] c. 70.0 N [W 53.l E] d. 50.0 N [W 53.l E]