In class Quiz #7-1
A person pulls a block across a rough horizontal
surface at a constant speed by applying a
force F. The arrows in the diagram correctly
indicate the directions but not necessarily the
magnitudes of the various forces acting on the
block. Which of the following statements must
be true?
A. F =k and N =W
B. F =k and N >W
C. F >k and N =W
D. F >k and N >W
E. None of the above
In class Quiz #7-1
A person pulls a block across a rough horizontal
surface at a constant speed by applying a
force F. The arrows in the diagram correctly
indicate the directions but not necessarily the
magnitudes of the various forces acting on the
block. Which of the following statements must
be true?
A. F =k and N =W
B. F =k and N >W
C. F >k and N =W
D. F >k and N >W
E. None of the above
Fx  k
Fy  N  W
In class Quiz #7-1
k < F and N < W
N
Fy
k
Fx
W
Everybody who answered gets 2 points for this question
In class Quiz #7-2
The traffic light has a weight
 of 100 N.
What is the vector tension T3 applied to the
point O?
1.
2.
3.
4.
Not enough
information
50 N
100 N
100 N
O
In class Quiz #7-4
For the same traffic light what is T1x  T2 x ?
1.
2.
3.
4.
Not enough
information
53 N
37 N
0.0 N
In class Quiz #7-5
For the same traffic light what is T1 y  T2 y ?
1.
2.
3.
4.
Not enough
information
100 N
100 N
0.0 N