1. Check your understanding
FORCES
Check your understanding

2. Two forces are exerted on an object
Two forces are exerted on an object. What third force would make the net force point to the left?
STT4.1
(1) (2) (3) (4)

3. Two forces are exerted on an object
Two forces are exerted on an object. What third force would make the net force point to the left?
STT4.1
(1) (2)
(3)
(4)

4. 1) Gravity, acting downward. 2) The normal force, acting upward.
You’ve just kicked a rock, and it is now sliding across the ground about 2 meters in front of you. Which of these forces act on the ball?
1) Gravity, acting downward.
2) The normal force, acting upward.
3) The force of the kick, acting in the direction of motion.
4) Friction, acting opposite the direction of motion.
5) 1, 2 and 4 but not 3.
STT4.2

5. 1) Gravity, acting downward. 2) The normal force, acting upward.
You’ve just kicked a ball, and it is now sliding across the ground about 2 meters in front of you. Which of these forces act on the ball?
1) Gravity, acting downward.
2) The normal force, acting upward.
3) The force of the kick, acting in the direction of motion.
4) Friction, acting opposite the direction of motion.
5) 1, 2 and 4 but not 3.
STT4.2

6. Two rubber bands stretched the standard distance cause an object to accelerate at 2 m/s2. Suppose another object with twice the mass is pulled by four rubber bands stretched the standard length. The acceleration of this second object is
1) 1 m/s2 .
2) 2 m/s2 .
3) 4 m/s2 .
4) 8 m/s2 .
5) 16 m/s2 .
STT4.3

7. Two rubber bands stretched the standard distance cause an object to accelerate at 2 m/s2. Suppose another object with twice the mass is pulled by four rubber bands stretched the standard length. The acceleration of this second object is
1) 1 m/s2 .
2) 2 m/s2 .
3) 4 m/s2 .
4) 8 m/s2 .
5) 16 m/s2 .
STT4.3

8. Three forces act on an object
Three forces act on an object. In which direction does the object accelerate?
(1) (2) (3) (4) (5)
STT4.4

9. Three forces act on an object
Three forces act on an object. In which direction does the object accelerate?
(1) (2) (3)
(4)
(5)
STT4.4

10. An elevator suspended by a cable is moving upward and slowing to a stop. Which free-body diagram is correct?
STT4.5
(1) (2) (3) (4) (5)

11. An elevator suspended by a cable is moving upward and slowing to a stop. Which free-body diagram is correct?
STT4.5
(1) (2)
(3)
(4) (5)

12. 1) The weight excluding the container
What is a “net force?”
1) The weight excluding the container
2) The vector sum of all forces in a problem
3) The vector sum of all forces acting on an object
4) The vector force applied by a net
5) The vector sum of all forces that add up to zero
IG4.1

13. 1) The weight excluding the container
What is a “net force?”
1) The weight excluding the container
2) The vector sum of all forces in a problem
3) The vector sum of all forces acting on an object
4) The vector force applied by a net
5) The vector sum of all forces that add up to zero
IG4.1

14. 1) Draw a closed curve around the system
Which of the following are steps used to identify the forces acting on an object?
1) Draw a closed curve around the system
2) Identify “the system” and “the environment”
3) Draw a picture of the situation
4) All of the above
5) None of the above
IG4.2

15. 1) Draw a closed curve around the system
Which of the following are steps used to identify the forces acting on an object?
1) Draw a closed curve around the system
2) Identify “the system” and “the environment”
3) Draw a picture of the situation
4) All of the above
5) None of the above
IG4.2

16. 1) is another name for the law of inertia.
Newton’s third law
1) is another name for the law of inertia.
2) says that the velocity of an object is determined by the net force on the object.
3) says that every action has an equal and opposite reaction.
4) was not discussed in this chapter.
IG4.4

17. 1) is another name for the law of inertia.
Newton’s third law
1) is another name for the law of inertia.
2) says that the velocity of an object is determined by the net force on the object.
3) says that every action has an equal and opposite reaction.
4) was not discussed in this chapter.
IG4.4