Riding in an elevator...force?
816694
hi \nbasic formula to be used here is f=ma\nhere we have 2 scenarios elevator going up(against gravity of earth denoted by 'g' which is constant eual to 9.8 or lets say 10m/s ^2.\nnow when elevator is going up means it has to defy gravity and go up which means there has to be more force to accomplish\nhence we use f=70 x (g+a)\nwhich is f= 70 x(10+3)=910N\nwhile the elevator is moving down it doesnt need to defy gravity and hence the force required to accomplish this will be much less\nhence we use f=70x (g-a)\nwhich is f=70x(10-3)=490N\n\nis the elevator is standing still then \nf=m x a\nwhich is f= 70 x 3 = 210n
1069669
gravity is stronger, leave it down
942786
The tension is the weight + the force Fb required to accelerate the bundle along with the rest of the elevator. \nNeed to calculate the elevator's acceleration a\ny = (1/2)*a*t^2 where y = 1m and t = 1.6s. Solve for a.\n\nNow calculate Fb\nFb = m*a. Solve for Fb.\n\nT = W + Fb
1049194
Things to do in an elevator:\n\n1) When there's only one other person in the elevator, tap them on the shoulder and then pretend it wasn't you.\n\n2) Push the buttons and pretend they give you a shock. Smile, and go back and go back for more. \n\n3) Ask if you can push the button for other people, but push the wrong ones.\n\n4) Call the Psychic Hotline from your cell phone and ask if they know what floor you're on.\n\n5) Hold the doors open and say you're waiting for your friend. After a while, let the doors close and say, "Hi Greg. How's your day your day been?"\n\n6) Drop a pen and wait until someone reaches to help pick it up, then scream, "That's mine!"\n\n7) Bring a camera and take pictures of everyone in the elevator.\n\n8) Move your desk in to the elevator and whenever someone gets on, ask if they have an appointment.\n\n9) Lay down a Twister mat and ask people if they'd like to play.\n\n10) Leave a box in the corner, and when someone gets on ask them if they hear something ticking. \n\n11) Pretend you are a flight attendant and review emergency procedures and exits with the passengers.\n\n12) Ask, "Did you feel that?"\n\n13) Stand really close to someone, sniffing them occasionally.\n\n14) When the doors close, announce to the others, "It's okay. Don't panic, They open up again."\n\n15) Swat at flies that don't exist.\n\n16) Tell people that you can see their aura.\n\n17) Call out, "group hug!", then enforce it.\n\n18) Grimace painfully while smacking your forehead and muttering, "Shut up, all of you, just shut up!"\n\n19) Crack open your briefcase or purse, and while peering inside, ask, Got enough air in there?"\n\n20) Stand silently and motionless in the corner, facing the wall, without getting off.\n\n21) Stare at another passenger for a while, then announce in horror, "You're one of THEM!" and back away slowly.\n\n22) Wear a puppet on your hand and use it to talk to the other passengers.\n\n23) Listen to the elevator walls with your stethoscope.\n\n24) Make explosion noises when anyone presses a button.\n\n25) Stare, grinning at another passenger for a while, and then announce, "I have new socks on."\n\n26) Draw a little square on the floor with chalk and announce to the other \npassengers, "This is my personal space!"\n\n27.) ask "excuse me, my butt itching, can anyone scratch it for me?" (you are holding things in your two hands)\n\n28.) Turn against the wall and start talking to the wall.\n\n29.) Look at your "invisivle" watch, and take your wrist and ask one of the people "Is this time right?"\n\n30.) Start hummong really loudly like you are meditating "UMMMMMMMMMMMMMMMMMMMMMMMMMMMM...\n\n31.) start doing jumping jacks.\n\n32.) Look at your hand and say out load "woooooow, coool" and wave your hand at the people and say "isn't it wow and cool?"\n\n33.) Sit on the floor and close your eyes, and start snoring really loudly.\n\n34.) Look suddenly at the floor of the elevator and start screaming at the "invisible" squirrel. \n\n==============================...\n\nHello, are you tired of your stinky butt, then get "Stink be Gone" for just 19.95 (plus shipping and handling) in three easy steps:\n\n1.) Take the Powder and apply it to your @$$\n\n2.) Rinse\n\n3.) and wait\n\n(4.) For best result take a dump outside and THEN use the "Stinkt Be gone" powder\n\nRemember, its very limited so call now!! at 1-800-butt-stink\nor go to www.stinkbutt.com
688313
Are you sitting down? Yes? Good. You are experiencing a force which is opposing gravity. The Earth's gravity is pulling down on your mass (i.e., weight = mass * gravity) and the chair that you're sitting on is pushing up on your butt with a force equal in magnitude to the gravity pulling down on you and in the opposite direction. The sum of the forces acting upon you is 0. (You could also just look at the equation F = m*a and say, "Well, I'm not accelerating, and I know that my mass is non-zero. Therefore, the total force acting upon me is 0. If that is true, and I know that gravity is always pulling down on me, there must be an equal and opposite force(s) acting upon me.")\n\nIf it's anti-gravity that you're asking about on the other hand... it doesn't exist. Stop watching Star Trek and start reading real physics books.\n\nAs for the comments about "NASA" in the answer above... this is exactly wrong. By letting the plane drop, they make it so that the ONLY force acting upon the subjects is gravity. The only thing that has gone away is the floor of the plane beneath the subjects, allowing them to "free fall" inside the plane. The occupants only "appear" weightless with respect to the reference frame of the spacecraft when in orbit about a planet. Gravity is ALWAYS acting upon both the spacecraft and its occupants. What happens is that the spacecraft and its occupants are both falling at the same rate. Gravity is what keeps it in the orbit and keeps it from floating off into space. You would have to be infinitely far away from the planet in order for the force of gravity to be zero.
939985
Well, yes, the gavity is pulling you down, and you are not moving. So you are subjected to an acceleration and are not moving.\nMind you, one can argue that the *resulting* force is zero, as the ground is reacting with an equal and opposite force to your weight; if you take it that way, to have an unbalanced force should result in motion.
979132
Use something to lift you up, that can support your weight.  such as:\nclear monofilament fishing line and a harness, or some kind of support that the audience can't see,\nor magnetic levitation
63054
People inside the plane are still being pulled down by gravity with a force of m*g=9.8*m.  The airplane is also holding the people within it with a force of m*v^2/r=22.22*m.  So you've got a horizontal force and a vertical force.\n\n      22.22*m\n---------------------->\n|\n|9.8*m\n|\nV\n\nPeople are most comfortable when they are accelerated into their seats (not the window or ceiling), so the bank angle will be perpendicular to the sum of those two vectors.  Your result should be about 65 degrees (though the 5 isn't a significant digit-- you should be able to get the final answer on your own).\n\nBut oh those poor people!  They'll be accelerated to almost 3 gs!
693885
Your problem cannot be solved if there's no other given. Lots of factors should be considered in fainding the probability to be stacked in an elevator such as the probability that the elevator will malfunction, probability that the elvator will take you to the second floor, third floor, fourth floor and so on and so forth.
284554
I believe that you are proposing to sit on the chair with your legs on the rungs and use your hands to lift up on the edge of the seat in order to lift the chair off the floor.\n\nThe short "scientific" answer is that this has never been done and even your own attempts have failed, right?  Science learns a great deal from empirical studies, cut and try.  Only one person must succeed to prove it can be done.\n\nScientists then go on to seek a reasonable explanation for what is observed.  Grasping and pulling on the edge of the seat produces a force that drives your body down into the seat.  What is needed is a force that pulls the chair up and away from the floor.  You could use your arms to pull up on a rope above you or your legs to push down on the floor below you.  Scientists would tell you that you must carefully define your system boundary.  When the system boundary includes only you and the chair (but not the room) you can only bend the chair but not lift it.  When the system boundary also includes the room, you can exert a force on the room (floor or ceiling) and move the chair relative to the room.\n\nThis is a great question to study how application of forces may be studied.  it applies in much more complicated configurations that are even harder to think about.
159363
Push it.  A mousetrap exerts force only for an short period of time.  You're not going to be able to make the car keep moving for very long.\n\nAlso, I don't know what "the string thing" is.  Perhaps you could explain this?
817519
hey ya.\nso, most of this question is irrelevant static.\nthe main point is, there's a patient on a tilted surface, and it might slide off. \n\nso if the patient isn't sliding off, what's keeping him from sliding down off the bed and onto the floor?\n\nif the answer is friction, then you are correct.\nif you don't think the answer is friction, what else could it be? alternatively, if the patient wasn't on a bed, but rather, on a greasy slide, it wouldn't take much of an angle for the patient to slide off.\n\nokay.\nso it's friction. \n\nyour book probably has done the old "friction between a slope with angle A and a box with mass M sitting on it" question to death. \n\nthe deal is that if you can't pass through a surface (so it's not made of water or jello or something), then it'll push back on you with a force pointing STRAIGHT out of the surface. this force is called the NORMAL FORCE. how much force does it push out with? the amplitude of the normal force is JUST ENOUGH to counteract the force you (or gravity) push down on it with. so. gravity will pull you down into it, and the normal force will push you back. \n\nanyway.... this is better explained with diagrams. look it up in your textbook. it's the old "incline plane" problem.
41805
Push them? :)\n\nWhat kind of "thins" do you want to move?
1064188
You're in a 750,000lb piece of metal that flys through the air.  Even if it is not that important, wouldnt you want to take every precaution to prevent any slight bit of chance of crashing?
930053
The force of static friction is the product of the force normal to the surface and the coefficient of friction. This force must be greater than or equal to the passenger's weight. First, we find the acceleration:\n\na = v²/r = ω²r, where ω is the angular velocity in rad/s\nω=.5 rev/s = π rad/s\na=4.6π² m/s² ≈ 45.40018 m/s²\n\nThe normal force producing this acceleration is:\nF = ma = m*4.6π² m/s²\nSo the maximum force of static friction is:\nμ*m*4.6π² m/s²\n\n(Note: those units are correct - I'm not writing the kg because the units of mass are contained in the term for mass - if I were to substitute a particular mass, I would get something like μ*(60 kg) * 4.6π² m/s², so writing kg a second time would be redundant).\n\nNow, the weight of a passenger is:\nF=mg ≈ m*9.81 m/s²\n\nSo we have:\nμ*m*4.6π² m/s² ≥ m*9.81 m/s²\n\ndividing by m*4.6π² m/s:\n\nμ ≥ 0.216079\n\nHowever, since our initial values were only given to two significant digits:\n\nμ ≥ 0.22
721588
Oh let him follow you. He's just stalking you.  It could get dangerous...but what the hey.  Seriously, if you have to ask this question, I'm not sure the elevator goes to the top floor.
792099
And the acceleration of the elevator is e.\n\nm*g = 477.1 N\nm*(g+e) = m*g + m*e = 652.4 N\n\nSolve for e.