Lesson: Weight and MassPhysics
In this lesson, we will learn how to calculate the weight of an object given its mass and its distance from an astronomical body.
Sample Question Videos
A body of mass 100 kg was weighed, using a spring scale, at the north pole and at the equator. Assuming at the north pole and at the equator, what was the difference between the two readings?
The force exerted by the Moon’s gravity at its surface is six times smaller than the force exerted by Earth’s gravity at its surface. The weight of an astronaut plus his space suit on the Moon is 250 N.
How much does the suited astronaut weigh on Earth?
What is the mass of the suited astronaut on the Moon?
What is the mass of the suited astronaut on Earth?
Astronauts in orbit are apparently weightless. This means that a clever method of measuring the mass of astronauts is needed to monitor their mass gains or losses, and adjust their diet. One way to do this is to exert a known force on an astronaut and measure the acceleration produced. Suppose a net external force of 50.0 N is exerted, and an astronaut’s acceleration is measured to be 0.893 m/s2. Calculate her mass.