Two sources of waves, call them A and B, send out waves across the surface of a lake. The waves from A have crests 1 cm high as measured from the normal undisturbed surface of the water. The waves from B are identical to those from A.
How far is the water displaced at a point where a crest from A crosses a valley from B?
A) 2 cm upward
B) zero
C) 1 cm upward
D) 1 cm downward
E) 2 cm downward
Question 2
You push your 2 kg physics book along a tabletop, pushing it with 10 newtons of force. If the book is greased so that friction is negligible, the book's acceleration is
A) zero.
B) 0.2 m/s2.
C) infinitely large.
D) 5 m/s2.
E) 20 m/s2.
