Answer:
Work, in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force
Explanation:
at least part of which is applied in the direction of the displacement. ... To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd.
Answer:
Weight of the woman in Newton

Mass of the woman in slug

Mass of the woman in kg

My weight in Newton

Explanation:
From the question we are told that
The weight of the woman in pounds is 
Converting to Newton
1 N = 0.22472 lb
x N = 157
=> 
=> 
Obtaining the mass in slug

Here 
So


Obtaining the mass in kilogram

Here 
So


Generally weight is mathematically represented as

Given that my mass is 80 kg then my weight is


Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is,
, were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as
, and the mass of the first and second coals as
and
respectively
We start with the transition between parts A and B, so we have:

Which means

And since we want the mass of the first coal thrown (
) we do:



Substituting values we obtain

For the transition between parts B and C, we can write:

Which means

Since we want the new final speed of the car (
) we do:

Substituting values we obtain
