Question

What is the mass of a metal sphere of
radius 3.0 cm, if its density is 7.0 g/cm3?
Express your answer in kg too.​

Answer 1

Answer:

113.1×7= 791.7 grams

Explanation:

density = mass/ volume

therefore mass = density×mass

volume of sphere =4/3 pie r³ that is 113.1.

Answer 2

Answer:

The mass of a metal sphere = 792 g

in kgs = 0.792 kg

Step-by-step explanation:

Given:

• Radius of a metal sphere = 3 cm
• Density of a metal sphere = 7 g/cm³

To find:

• The mass of a metal sphere.

Solution:

Here, we will simply use the formula of mass when density and volume are given. We will find the volume of a metal sphere by using formula of a volume of a sphere. Putting the values in the formula and then doing the required calculations.

✰ Mass = Density × Volume

( N.B: Volume of sphere = 4/3 πr³

Where,

r is the radius of a metal sphere. )

Putting the values,

• Mass of a metal sphere = 7 × 4/3 × 22/7 × 3³
• Mass of a metal sphere = 7 × 4/3 × 22/7 × 3 × 3 × 3
• Mass of a metal sphere = 7 × 4 × 22/7 × 3 × 3
• Mass of a metal sphere = 4 × 22 × 3 × 3
• Mass of a metal sphere = 88 × 9
• Mass of a metal sphere = 792 g

Expressing it in kg...

• 1 g = 1/1000 kg
• 792 g = 792/1000
• = 0.792 kg

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