Can anyone tell me the practice questions for Chapter 1 of Grade 8 Physics 5

Section 1 Force.

6.②④7.Size Direction 8Equal to the hardness of the drawing problem.

11.How to Operate Experimental Phenomena.

Pinch the balloon firmly with your hand The balloon has become deflated.

Pinch the balloon lightly with your hands and pinch the balloon lightly The balloon is flattened to a different degree.

Touch the two balloons into each other and squeeze both balloons are flattened.

Section 2 Elasticity.

5.The pointer zero tick mark is large.

1 34 7.Elongate the tensile length.

8.(1) 1 2 3 4 (2) Within a certain range, the elongation of the spring is proportional to the tensile force (or within a certain range, the greater the tensile force on the spring, the longer the elongation).

9.(1) It can magnify the reflection of light through the plane mirror, which is easy to observe.

2) The desktop is elastically deformed, and the light spots on the wall will move after the desktop is compressed; After the pressure was removed, the light spots on the wall returned to their original positions.

Section 3 Gravity.

6.Earth 1 7Vertical down 5 85 10 Vertical Drawing Questions.

11.(1) Spring dynamometer balance (2) (3) The gravitational force exerted on objects around the earth is proportional to their mass.

12.Solution: The volume of each steel plate is.

v＝2m×1m×

The total mass of 10 steel plates is.

m＝10pv

The total gravity of the 10 steel plates is:

G mg to the 4th power n

Because of the 4th power n of the 4th n, the rope can withstand these plates.

The teacher sent us the answers, and they were all right.

Do it yourself, lazy is not a good child.

Section 1: 1. Electricity consumption in June, electricity fee = 98 * yuan, electricity fee in July = 150 * yuan. 2.

15 degrees * yuan degrees = yuan. 3.If the year is 52 weeks, the electricity cost = 52 * yuan.

4.Do not turn on the sleep light, so that the lights are turned off when people walk, and energy-saving electrical appliances are used.

Section 2: pcs) is about 6 small bulbs in series. 2.When introducing energy saving, the reporter ignored the working hours of electrical appliances, and one-sidedly emphasized the electrical power of electrical appliances.

100w/(454*

European Education Edition 8th Grade Physics Workbook 24 Pages 14 and 15 Question Answers:

14.(1)4v(2)r1=u1:i1= r2=u2:i2=15.(1)i2=i-i1= (2)r1=u:i1= r2=u:i2=:i=

Chapter VIII Electrical Power I. Electrical Energy 1Light energy d d 6Wind series electric energy 15

Photoelectric energy saving and environmental protection 16and 110kw*h Second, the electric power 3 uses the frequency 5Move 120j