in which the motion of a body depends on the point on which the force is applied. Please explain.
2006-09-18 03:53:13 · 10 answers · asked by kafka 1 in Science & Mathematics ➔ Physics
What you probably mean is "It is sometimes very important to consider WHERE a force is applied...."
Consider a teeter totter. If you sit down on it in the middle, right over the fulcrum where it rocks around, the perfectly balanced TT will stay level. But if you move off of center just a bit, the TT will drop on the side you are now sitting while the other side springs upward.
Same weight, which is a force, but different results depending on where you sit. What you experience, when doing this mental experiment, is something called moment (not momentum); where moment is defined as force acting on some body at a distance from the point where that body rotates. In math talk M = F X S; where F is the force and S is the distance from the rotational point (like the fulcrum on the TT).
Moment tends to cause things to rotate around the rotational point. But it can also be used to prevent rotation. For example, back to the TT, if you have a partner join you on the teeter totter, the two of you can sit at just the right distance on either side of the fulcrum to keep the teeter totter level. That's because your moment and your partner's moment are equal, but in opposite directions. They cancel each other out; so the TT stays level with the ground.
In math talk M = (F X S) - (f X s); where the F is you sitting S feet from the fulcrum and the f is your partner sitting s feet from it on the other end of the TT. So to keep the TT level, M has to be = 0; in which case F X S = f X s. The two moments are equal in value.
Moment has very practical applications. For example, the space shuttle maneuvers by using small rocket jets to push it around its center of gravity (COG), which is its fulcrum. One spurt of a jet will start the shuttle spinning in one direction until a spurt from another jet, but pointing in the opposite direction, stops that spin.
2006-09-18 04:27:34 · answer #1 · answered by oldprof 7 · 0⤊ 0⤋
Well, if the object on which the force is applied is three dimensional then the force may cause it to spin more than to move any any given direction if the force is applied away from the Center of Gravity of the object. A force can also cause the COG to be raised which may cause an otherwise stable structure to fall over. There are many more examples.
2006-09-18 04:00:42 · answer #2 · answered by Nightstalker1967 4 · 0⤊ 0⤋
When you're closing a door--torque.
The motion of the door is dependent upon the point at which you apply force (that force being in this case torque). If you apply your force close to the axis of rotation, the door will accelerate slowly and more force is needed to produce the same rate of acceleration at which the door will open. Conversely, if a force is applied far from the axis of rotation, the door will accelerate faster (even if the same force is applied as in the first scenario I just explained).
Get it...?
2006-09-18 05:00:50 · answer #3 · answered by Angela 3 · 0⤊ 0⤋
To answer this question we use a model. In this case a stalled car.
When we try to get the car off the road we need to move it.
AS soon as a man applies power (one who has stored a lotter power in his body) He feel a lot of force . That means acceleration is a maximun. As the car moves and increases speed the man feels less force till the car moves to its speed the force felt is practically zero.
In order to make the car move faster that additional power must be used in this case the man can only deliver a certain amount of power and that is it.
Another Experiment would be peddling a bicycle. When the bicyle has reached a certain speed it requires less effort to pedal.
Note forces dont get applied to make an object move; but Power is what makes a car move.
2006-09-18 05:09:16 · answer #4 · answered by goring 6 · 0⤊ 0⤋
welll according to newton's 2nd law, the force acting on a body is directly proportional to the rate of change of momentum and the force is acting in the direction of the momentum.
F= d(mv)/dt
therefore when v = +ve, F = +ve, the force acting on the object is in the same direction at which the object is travelling.
an example would be you pushing a ball on the table.
2006-09-18 04:22:34 · answer #5 · answered by superlaminal 2 · 0⤊ 0⤋
Billiard
2006-09-18 04:55:45 · answer #6 · answered by morganna_f 3 · 0⤊ 0⤋
a Rocket Launch
2006-09-18 04:03:20 · answer #7 · answered by bostoncity_guy 2 · 0⤊ 0⤋
You tell us
2006-09-18 03:55:38 · answer #8 · answered by Anonymous · 0⤊ 0⤋
not clear
2006-09-18 05:15:49 · answer #9 · answered by openpsychy 6 · 0⤊ 0⤋
car crash
2006-09-18 04:02:37 · answer #10 · answered by bullyhouse123 2 · 0⤊ 0⤋