Can someone please explain how to determine the force of a person in term of their weight??? I really have tried, I cant seem to get it. Do I use F=ma and w=mg and replace m in the force equation with w/g??? I've tried everything and I dont think I quite understand what I'm looking for. Will someone please explain what it is the question is asking for? Thanks in advance!
2007-03-26 12:51:55 · 4 answers · asked by asdfk23 1 in Science & Mathematics ➔ Physics
Weight is the force due to gravity. You find weight by putting the thing to weigh on a weighing scale...like your bathroom scale. If you weigh a petite 96 pounds soaking wet, then the force of gravity on your body is 96 pounds.
Your weight does not depend on level ground, as one person indicated. Weight always acts downward, toward the center of mass of the body causing the gravity...like our Earth.
That is not to say other forces cannot be acting on your body or other kind of mass. But the weight, by definition, always points toward the center of mass...the center of our Earth for those of us living here.
You've clearly heard of F = ma; where F is a force, m is a mass the force is acting on, and a is the acceleration due to that force. When that force is weight (force due to gravity) we write F = ma = W = mg; where g is the aceleration of the force due to gravity, which we call weight.
g is special because for a given mass and a given distance from the center of mass, g is a constant. That is, no matter how massive a body is, it will always (I repeat always) be accelerated at a given g for that mass and distance from its center.
For example, g = 9.81 m/sec^2 or 32.2 ft/sec^2 always when the attracting mass is the Earth and the distance of the attracted body from Earth's center puts the body on Earth's surface. What does this mean?
If you drop a golf ball and a bowling ball from the same height, both will hit the ground at the same time. Why? Because w/m = g = W/M; where w and m are the weight and mass of the golf ball and W and M are for the bowling ball. That's right, they both accelerate at the same 9.81 m/sec^2 or equivalent 32.2 ft/sec^2...the acceleration due to the force of gravity.
2007-03-26 13:48:43 · answer #1 · answered by oldprof 7 · 0⤊ 0⤋
the force a person would exert on a surface where he/she was standing would be their mass times the acceleration due to gravity, ex; a person weigthing 100kg would exert a force on the floor of 981 Newtons (g = 9.81 m/s^2) but this is only true if surface was horizontal otherwise you have to concider the angle the surface makes with the horizontal in which case the normal force that the person exerts on the surface would be mgsin(theta) or what ever you want to call your angle.
2007-03-26 20:07:41 · answer #2 · answered by evilotto 2 · 0⤊ 0⤋
Weight IS force- the force of gravity on an object.
2007-03-26 19:57:18 · answer #3 · answered by Chad P 3 · 0⤊ 0⤋
Your weight (in N) is w=mg
weight=w (N)
mass=m (g)
gravity (9.8 m/s/s)
2007-03-26 20:09:19 · answer #4 · answered by Anonymous · 0⤊ 0⤋