Multiple choice question: C C
Fill in the blanks: (4) two, four (5)-2 (6) y = 90/x (x >; 0)
Solution: 7. (1) Draw by yourself, in the first quadrant.
(2) let I = k/r.
Substitute R=2 and I=6.
6=K/2
K= 12
∴I= 12/R
(3) When I= 1.5
0.5= 12/R
R=24
A: It is 24 ohms.
8.( 1) Let p = k/v.
Substitute P= 123 and V=0.8.
120=k/0.8
k=96
∴P=96/v
(2) when P= 140
140=96/v
v=24/35
∴V≥24/35
Answer: Not less than 24/35m? .
9.( 1) Let p = k/s.
Substitute P=400 and S= 1.5.
400=K/ 1.5
K=600
∴P=600/S
The value range of independent variable s: S>0.
(2) when S=0.2
p=600/0.2
p=3000
A: It's 3000 Pa.
(3) when P=6000
6000 = 600/ sec
s=0. 1
∴S≥0. 1
A: At least 0. 1㎡.
I was exhausted from playing. What is the third chapter about testing and evaluation? Report pages or give questions.