Question

Calculate the weight of the following objects, or Earth's (assume g=10N/kg).a)12kg b)500g c)20g

Answer 1

a) W = 120 N

b) W = 5 N

c) W = 0.2 N

Step-by-step explanation:

There are given three objects with different mass values. The formula of weight is:

`\displaystyle{ W= mg}`

Where W is weight, m is mass and g is acceleration due to gravity. Since, we are finding the objects' weight on Earth then we have to use g = 10 N/kg (m/s²) which is already given in the problem. Therefore, see below for various parts:

A) 12 kg

Substitute in m = 12 kg, g = 10 N/kg

`\displaystyle{W = 12 \: \text{kg} \cdot 10 \: \text{N/kg}} \\ \\ \displaystyle{W = 120 \: N}`

Therefore, a mass of 12 kg on Earth will have weight of 120 N.

B) 500 g

Since the unit is in grams, we have to convert to kilograms in order to evaluate for weight. We know that 1000 gram = 1 kilogram and therefore, 1 gram = 0.001 kg. Hence, 500 grams = 1/1000 * 500 kg which equals to 500 grams = 0.5 kg

`\displaystyle{W =0.5\: \text{kg} \cdot 10 \: \text{N/kg}} \\ \\ \displaystyle{W = 5\: N}`

Therefore, a mass of 500 g on Earth will have weight of 5 N.

C) 20 g

We know that 1 gram = 1/1000 kilogram. Therefore, 20 grams = 1/1000 * 20 kg which results in 20 grams = 0.02 kg

`\displaystyle{W =0.02\: \text{kg} \cdot 10 \: \text{N/kg}} \\ \\ \displaystyle{W = 0.2\: N}`

Therefore, a mass of 20 g on Earth will have weight of 0.2 N.