How to calculate the weight in newtons?

Question

If I have a sheet of copper with a diameter of 20.0cm and a thickness of 2mm. I am trying to work out a problem but I have no idea how to figure this out. I need a detailed answer please. Thanks in advance.

Answer 1

First, weight is in terms of grams and kilograms.  A newton is one kg that is acclerated at 1 m/sec^2, if I remember right.   On earth, the earth's accleration is 9.8 m/sec^2, so whatever kg you compute will be multiplied by that to get newtons.

You have to find the weight of your copper disk.  Its volume, in cm^3, is  pi (10^2) (0.2) or 20 pi  cm^3.  You can look up the density of copper in Wikipedia, and multiply the volume by that density to get GRAMS.  Now you divide that weight by 1000 to get kgs.    

Answer 2

If you want to calculate the weight,(on earth) you have to find the mass,then multiply it by 9.8m/sec^2 for kg to newtons or 32ft/sec^2.

(slug to pounds.)Always have in your mind that a weight of 1lb has a mass of 0.453 kg on our earth.

Answer 3

1. Compute the area:

π r² = π (10)² = 314.159 cm²

2. Compute the volume:

area * thickness

(314.159 cm²) (0.2 cm) = 62.8318 cm³

3. Look ip the density of copper:

8.96 g/cm³

4. Compute the mass

mass = volume * density

m = 62.8318 cm³ * 8.96 g/cm³ = 562.972928 g

m = 0.562972928 kg

5. Compute the weight

w = mg

w = 0.562972928 kg * 9.81 m/s²

w = 5.52276442368 N

Double check my math.