Body weight is the force with which it presses on the horizontal support preventing free fall of a body. In life you can call powerful mistakenly weight. It's not true: if the person costs on a floor, goes on the elevator up or down, weight it is invariable, and weight will change.
Instruction
1. Body weight is measured in Newtons. To find the weight of your body at rest under normal terrestrial conditions, use a formula P=mg where P is a weight, m – the weight, g – acceleration of gravity (or acceleration of gravity). Means if the mass of your body, for example, of 60 kg, its weight is equal to 60x9.81=588.6 (N).
2. If you in the elevator go down, you can feel some ease. It is connected with the fact that at the same body weight the weight decreased. In this case weight is calculated by a formula P=m (g-a) where and – acceleration of a body, in this case is equal to 2 m/s². Respectively the weight of your body will be equal 60x (9.81-2)=468.6 (N) now. In comparison with the first case the weight decreased by 120 Newtons.
3. When you rise on the elevator, feel weight. As the vector of acceleration is directed against gravity, for calculation of weight you receive a formula P=m(g+a). Acceleration is known to us, it is also equal to 2 m/s². It turns out that body weight is equal 60x (9.81+2)=708.6 (N). In comparison with your weight at rest, the new indicator is 120 Newtons more.
4. At trainings of astronauts the situation when the plane was entered intentionally into a condition of falling was used. What your weight would be if you were on similar exercises? It will turn out that you and the plane are in a condition of free fall, so, on the plane your weight is calculated by a formula P=m (g-a), an in this case equals g, so of P=m (g-g), P=60x (9.81-9.81)=60x0=0 (N) follows from here. It is called weightlessness state, your weight is equal in the falling plane to zero as well as in space.
5. On other planets with the same weight and acceleration your weight will differ. For example, on the Moon the acceleration of gravity is equal to 1.62 m/s², so, your body at rest on the Moon will weigh 60x1.62=97.2 (N) that is 491.4 Newton less, than on Earth.