**Revision On Unit 1**

Write the scientific term ...

1- The amount of matter in an object. ( ……………… )

2- The force with which the body is attracted to the earth. ( ……………… )

3- The measurement unit of mass which is almost equal to a mass of liter of water. ( ……………… )

4- The measurement unit of weight which is almost equal to a mass 100 grams. ( ……………… )

5- A device that is used to measure the mass of chemicals in lab. ( ……………… )

6- A device that is used to measure the weight of an object.( ……………… )

problems

Problem (1):-

If an object's mass on earth = 30 kg

Calculate:-

1- It's mass on Moon.

2- It's weight on earth.

3- It's weight on Moon.

Problem 2

Problem (2):-

If your weight on earth = 600 Newton. Calculate your weight on the moon.

Problem 3

Problem (3):-

If an object's weight = 20 Newton. Calculate it's mass.

Complete the following ززز

1- Mass is measured by using ………….. , where as weight is measured by using …………..

2- If the weight of iron ball is 200 Newton, so it's mass equals …

3- The measuring unit of mass is ………….. or ………….. where as the measuring unit of weight is …………..

4- The ……………………..decreases when the distance between an object & the center of the earth increases.

5- …………..is the force by which a body is attracted to the earth.

6- The object's weight depends on ………….. , …………..………….. & …………..…………..…………..

7- Mass is a constant value & not affected by …………...

8- …………. is the amount of matter in an object.

9- …………..is the measuring unit of mass & equals to the mass of one paper clip.

10- …………..is the measuring unit of mass & equals to the mass of one liter of water.

11- Newton is the measuring unit of weight which equals …………..grams.

**Mr.Ahmed Elbasha**

1.Mass

2.Weight

3.Kilogram

4.Newton

5. Balance Scale

6.spring scale

Answer:

1- Mass on moon = 30 kg

Because : the mass has fixed value

2- Weight on Earth = mass (kg) x 10

= 30 x 10 = 300 Newton

3- Weight on moon = W on Earth / 6

= 300 / 6 = 50 Newton

Answer:

W on moon = W on Earth / 6

= 600 / 6 = 100 Newton

problem 4

Problem (4):-

If an object's mass = 200 gm. Calculate it's weight on both earth and moon surfaces.

Answer :

We need to find Mass (m)

So ; m = w / 10

= 20 / 10

= 2 Kg

Answer :

First step convert 200 gm to Kilogram

200gm = 200/1000=0.2 kg

Then;

Weight on Earth = mass (kg) x 10

= 0.2 x 10 = 2 Newton

Weight on moon = W on Earth / 6

= 2 / 6 = 0.333 Newton

Answer ;

1- Kilogam - Newton

2- 20 kilogram

3- Gram - kilogram - Newton

4-Weight

5-weight

6- The object mass - Distance from the object and the center of the earth - planet where the object exist .

7- Changing the place

8-Mass

9-Gram

Give reason for:-

1- The weight of an object is affected by its mass.

2- There is a relation between mass & motion.

3- The weight of a person on the earth is larger than its weight on moon.

4- An object's weight is affected by the distance being away from the center of the earth.

5- The moon's gravity is less than earth's gravity.

1- Because as mass increases the weight increases.

2- Because the more object's mass increases, the more difficult to change it's speed.

3- Because earth has greater mass & gravitational force than moon.

4- Because the gravity force decreases as the body moves away from the earth so it's weight decreases.

5- Because the mass of moon is less than that of earth & as mass of the planet increases it's gravitational force increases.

Answer

Thank You

Mr.Ahmed Elbasha