Question

On a given planet, the weight of an object varies directly with the mass of the object. Suppose that an object whose mass is 2 kg weighs 4 N. Calculate the mass of another object that weights 18 N.

Answer 1

Let m be the mass of the object and w be the weight of the object. According to the problem, weight varies directly with mass, so we can write:

w = k * m

where k is the constant of proportionality.

To find k, we can use the information given in the problem. We know that when m = 2 kg, w = 4 N. Substituting these values into the equation above, we get:

4 N = k * 2 kg

Solving for k, we get:

k = 4 N / 2 kg = 2 N/kg

Now we can use this value of k to find the mass of an object that weighs 18 N. We can rearrange the equation above to solve for m:

m = w / k

Substituting w = 18 N and k = 2 N/kg, we get:

m = 18 N / 2 N/kg = 9 kg

Therefore, the mass of the object that weighs 18 N is 9 kg.