Mass Weight And Density

Question 1

Define weight

Answer 1

Is the force with which an object is attracted to the centre of the earth

NB. Scalars needs directions

Question 2

Give the formula that shows the relation between mass and weight

Answer 2

W = mg

Question 3

Define Density

Answer 3

It is the ratio of mass to volume

Question 4

Give the formula for density

Answer 4

P= m/v. (Roe). In g.cm-3

Question 5

Give the general rule concerning density’s relation to temperature

Answer 5

As the temperature increase, the density lowers

Question 6

Determine the density of a regular shapes block. Describe how it is done

Answer 6

Determine its mass on a balance scale

Determine its volume by measuring it’s dimensions. Calculate it’s volume

Now calculate it’s density by using formula p=m/v

Question 7

Determine the density of an irregular shaped object

Answer 7

Determine the mass of the object using a balance scale

Fill measuring beaker with enough water to cover the object and record it’s volume

Carefully slide the object into the water (not to splash)

Note total volume and do subtraction to calculate the volume of object

Now calculate density by using mass / volume

Question 8

Determine the density of a gas

Answer 8

Page 32

Question 9

Determine density of a liquid

Answer 9

P 32

Question 10

The mass of a man on earth is 100kg

What is his mass on the moon (with a gravitational force of about 1/3 that of earth?

Answer 10

100kg

Question 11

What is the weight of a man with mass 100kg on earth. g = 10m.s-2

Answer 11

W=m.g

= 100 kg x 10m/s2
= 1000N. Downwards

NB. mass in kg

Question 12

Calculate the density of an unknown substance with mass = 100g and volume = 2 dl

Answer 12

1. Calculate the mass in g
   100g
2. Calculate the volume in cm^3
   2 dm = 20cm
   2 dm^3 = 20^3 = 8000 cm^3
3. P= m/v. =0,1/8000 g/cm^3

Question 13

Define Mass

Answer 13

It is the measure of inertia of a body