28. If an object is moving and there are no unbalanced forces acting on it, the object will
a. speed up.
b. slow down.
c. continue moving at constant velocity.
d. none of the above
29. If you push on your textbook so that it slides across the table at a constant velocity,
a. there must not be any forces acting on the book, otherwise it would accelerate.
b. all of the forces acting on the book must be balanced.
c. the book must be changing direction.
d. none of the above
30. If you drop your textbook, while it is falling it speeds up, therefore
a. there are no forces acting on the book.
b. all of the forces acting on the book are balanced.
c. the forces acting on the book are unbalanced.
d. none of the above
31. Objects at rest tend to remain at rest and objects in motion tend to remain in motion, unless
acted upon by an unbalanced external force. This is a basic description of
a. Newton’s 1st Law
b. Newton’s 2nd Law
c. Newton’s 3rd Law
d. Newton’s 4th Law