Mass and Weight

Question

At the surface of Mars the acceleration due to gravity is 3.8 m/s2. A book weighs 34 N at the surface of the Earth. What is its mass on the earth’s surface? What are its mass and weight on Mars’s surface? 

Answer 1

A newton is a unit of force so we can use one of newtons laws F = m*a

We know the book weighs 34 Newtons on Earth and the acceleration due to gravity on Earth is 9.81 m/s^2.

We can use F = m*a to solve for the mass, since mass isn't dependent on the gravitational pull around it.

34 N = m * 9.81 m/s^2

m = 3.466 kg on earth

We can then use the same equation to find the weight on mars.

Here we are using the acceleration due to gravity on Mars.

F = 3.466 kg * 3.8 m/s^2

F = 13.17 N on Mars

**Note: Weight is dependent on the gravitational field where the object exists because it is dependent on the acceleration, where as mass does not and is the same everywhere. A force and weight are, for the purpose of this problem, the same thing.**