QUIZ 2

Exercises and Problems from Conceptual Physics: Note that answers to odd numbered problems are  listed in the paperback supplement "Practicing Physics."

Ch 4

exercises

7

8

14

33

39

49

53

problems

2

3

4

7

8

Ch 5

exercises

 2

7

9

problems

 1

2

4

6

Real Quiz 2

Hints:

 Ch. 4

exercises

 53.
Before the body reaches terminal velocity, the upward force of the air resistance is less than the downward force of gravity; in this case the acceleration is downward but less than g in magnitude.  For example net force downward =
 ma = mg – R. If you solve for a, you will get an answer for a <g.

When the body reaches its terminal velocity, the upward and downward forces are equal; in this case the acceleration is ZERO since  ma = mg – R = mg – mg = 0. (R = mg in this case.)

 problems

 2.  a = F/m

 4. a = F/m =  2 N/ 2 kg. Note that the acceleration is the same as the first case since you are doubling both the force and the mass.

 8.  net force down = ma = mg – mg/2 = mg/2 . Solve for a.

 Ch. 5

 exercises

2. 
(a) hammer force on nail is action and nail force on hammer is reaction (b) Earth force on book is action and book force on earth is reaction
(c) same concept as (a) and (b) 

9. The action force is ball on floor and the reaction force is floor on ball.. The reaction force  causes ball to bounce upward after  contact with floor...

problems

2.  30N in the opposite direction as your push force. a = F/m

4. F² = 3²  + 4² . Solve for F and use a = F/m . 

6. v² = 3²  + 4²   Solve for the speed v.