5 Sc P 13 2

David and Peter were moving a bookshelf across the carpet in their classroom. Even though they pushed as hard as they could, the bookshelf would only move a few inches at a time.  
Which of the following best explains what happened as they tried to push the bookshelf?

• The force of gravity opposed the motion of the bookshelf
• The force of friction opposed the motion of the bookshelf
• When they tried to push the bookshelf, air resistance acted against them
• When they pushed the bookshelf, the bookshelf pushed back with an equal and opposite force

Philip is playing tug of war with Nancy. They both understand that to win the game of tug of war, one player must pull the flag over their opponent's line, but during this particular game, the flag tied to the center of the rope is not moving.  
What is happening to the rope in this example?

• Philip is applying more force in one direction
• Nancy is applying more force in one direction
• Philip and Nancy are applying equal forces in the same direction
• Philip and Nancy are applying equal forces in opposite directions

While on a camping trip, Shane and Katie are traveling in a boat on a river. On their trip, the river's current carries them down the river at a speed of 5 meters per second (m/s). They don't need to row because the current is carrying them in the direction they need to go.  
If no other forces are acting on the boat, which of these statements describes the motion of the boat as it travels downstream?

• it speeds up
• it slows down
• it stays the same
• it changes direction

Will and Tammy are moving a dresser. They are arguing about which direction to move it. Will is pushing the dresser with a force of 5 newtons towards Tammy. Tammy is pushing the dresser towards Will with a force of 10 newtons. What happens to the dresser?

• The dresser does not move
• The dresser moves towards Will
• The dresser moves towards Tammy
• The dresser moves towards Tammy, then back towards Will

Maria pushes with equal force on two objects. Object 1 has twice as much mass as Object 2. Which of the following statements is true?

• Both objects will remain still
• Object 1 will accelerate faster than object 2
• Object 2 will accelerate faster than object 1
• Both objects will accelerate at the same rate

Candice is rearranging the furniture in her room. She has two different dressers that are the same size. When she pushes on each dresser, she finds that it is harder to move Dresser A than it is to move Dresser B.  
Why does Candice have to push with more force on Dresser A than on Dresser B?

• Dresser A weighs less than Dresser B
• Dresser A is larger in size than Dresser B
• Dresser A has more mass than Dresser B
• Dresser A has less volume than Dresser B

Julian rides in her mother's car sometimes and in her father's car other times. If it takes her less time to travel the same distance in her mother's car than in her father's car, which of the following is true?

• Her father's car is traveling at a greater speed than her mother's car
• Her mother's car is traveling at a greater speed than her father's car
• Both cars are traveling at the same speed since they travel the same distance
• Both cars accelerate at the same rate, but her mother's car has a greater mass

Jonathan pushes a box on the floor and is unable to make it move. Which of the following is the best explanation for why the box does not move?

• The box has a very small mass
• Jonathan is pushing in the wrong direction
• The mass of the box requires a greater force to move it
• Friction occurs in the same direction that Jonathan is pushing

If all the forces acting upon an object at rest are balanced, what will the object do?

• The object will stay still
• The object will slow down
• The object will accelerate
• The object will change position

Darryl pushes on two different boxes. Box 1 has a greater mass than Box 2. Which of the following statements is true?

• Equal force is needed to move the boxes
• Both boxes will accelerate at the same rate
• Less force is required to move Box 1 than Box 2
• Less force is required to move Box 2 than Box 1