What is Apparent weight: Definition and 71 Discussions
In physics, apparent weight is a property of objects that corresponds to how heavy an object is. The apparent weight of an object will differ from the weight of an object whenever the force of gravity acting on the object is not balanced by an equal but opposite normal force. By definition, the weight of an object is equal to the magnitude of the force of gravity acting on it. This means that even a "weightless" astronaut in low Earth orbit, with an apparent weight of zero, has almost the same weight as he would have while standing on the ground; this is due to the force of gravity in low Earth orbit and on the ground being almost the same.
An object that rests on the ground is subject to a normal force exerted by the ground. The normal force acts only on the boundary of the object that is in contact with the ground. This force is transferred into the body; the force of gravity on every part of the body is balanced by stress forces acting on that part. A "weightless" astronaut feels weightless due to the absence of these stress forces.
By defining the apparent weight of an object in terms of normal forces, one can capture this effect of the stress forces. A common definition is "the force the body exerts on whatever it rests on."The apparent weight can also differ from weight when an object is "partially or completely immersed in a fluid", where there is an "upthrust" from the fluid that is working against the force of gravity. Another example is the weight of an object or person riding in an elevator. When the elevator begins rising, the object begins exerting a force in the downward direction. If a scale was used, it would be seen that the weight of the object is becoming heavier because of the downward force, changing the apparent weight.The role of apparent weight is also important in fluidization, when dealing with a number of particles, as it is the amount of force that the "upward drag force" needs to overcome in order for the particles to rise and for fluidization to occur.
Homework Statement
This question is continued from a problem that I have already solved. This is what I know from the previous problem that will be helpful:
r= 0.20 m
roh of solid sphere= 850 kg/m^3
mass sphere= 3.94 x 10 ^-5 kg
I also have 2 apparent weights that I solved for when...
Homework Statement
Planet X rotates in the same manner as the earth, around an axis through its north and south poles, and is perfectly spherical. An astronaut who weighs 950.0 N on the Earth weighs 919.0 N at the north pole of Planet X and only 855.0 N at its equator. The distance from the...
Homework Statement
What is the apparent weight of a 75 kg astronaut 2500 km from the center of the Moon in a space vehicle (a) moving at constant velocity and (b) accelerating towards the moon at 2.3 m/s^2. State direction in each case.
Homework Equations
F=Gm1m2/r^2 and F=mg
The...
Homework Statement
Referring to the problem above, if the elevator's descending speed is measured at 10 m/s at a given point, but its speed is decreasing by 2.5 m/s2, what is her apparent weight?.
And the problem above it was this
A 58.0 kg girl weighs herself by standing on a scale in an...
Homework Statement
You are standing on a bathroom scale inside an elevator. Your weight is 160 lb, but the reading of the scale is 123 lb.
(a) What is the magnitude and direction of the acceleration of the elevator?
? m/s2
(b) Can you tell whether the elevator is speeding up or slowing...
Homework Statement
A man with a mass of 85.0 kg rides downward on an elevator.Initially the elevator accelerates downwards at 1.845 m/s^2 and eventually slows at 1.60 m/s^2 as it reaches the ground floor. Find the mans apparent weight as he starts down and as he reaches the ground floor...
Communications satellites are placed in a circular orbit where they stay directly over a fixed point on the equator as the Earth rotates. These are called geosynchronous orbits. The altitude of a geosynchronous orbit is 3.58 x 10^7m. What is the period of the motion? What is the value of g at...
Not original #'s but same questions:
Homework Statement
A 750N child rides a ferris wheel that is moving at a constant velocity. At the highest point the child has an apparent weight of 650N.
(a) what is the acceleration of the wheel?
(b) what is the apparent weight of the child at the...
Homework Statement
Henry gets into an elevator on the 50th floor of a building and it begins moving at t=0s The figure shows his apparent weight over the next 12s.
http://img520.imageshack.us/img520/8404/knightfigure0530ry3.th.jpg
What is Henry's mass?
How far has Henry traveled at t =12s...
The passengers in a roller coaster car feel 50% heavier than their true weight as the car goes through a dip with a 20.0 m radius of curvature.
What is the car's speed at the bottom of the dip?I'm stuck on this problem. I understand that at the bottom they feel 1.5 times heavier. Other than...
I'm trying to understand the utility of the concept of apparent weight. I'm not trying to over throw centuries of science, but it just seems not to be very useful to me.
Why is it useful to say 'the apparent weight in an accelerating elevator is more (less)' rather than to just say 'you weigh...
Can someone tell me what I'm doing wrong here?
When you weigh yourself on good old terra firma (solid ground), your weight is 126 lb. In an elevator your apparent weight is 118 lb. What are the direction and magnitude of the elevator's acceleration?
I have Wa = W-ma = mg-ma
Wa=118lb...
Circular Motion
Situation:
A concrete highway curve of radius 70m is banked at a 15 degree angle.
Question:
What is the max speed with which a 1500kg rubber-tired car can take this curve without sliding?
Feedback:
I learned that the static coeffiecient of friction of rubber on concrete...
2) a small container of water is placed on a carousel inside a microwave oven, at a radius of 12.0 cm from the center. The turntable rotates steadily, turning through one revolution in each 7.25s. What angle does the water surface make with the horizontal?
3) a person stands on a scale in the...
Hi! I'm beginning a whole new unit in physics, that I'm not that sure of. Any suggestions would be appreciated as to how to tackle these following questions:
1) the pilot of an airplane executes a constant-speed loop the loop maneuver in a vertical circle. the speed of the airplane is...
A roller coaster car crosses the top of a circular loop-the-loop at twice the critical speed.
What is the ratio of the car's apparent weight to its true weight?
from my notes i have that Velocity_critical= squareroot ( r w / m)
v = sqrt(rw/m)
so what i did was multiply v times...
what is the apparent weight of a 65 kg astronaut 4200 km from the centre of the moon in a space vehicle a) moving at constant velocity, and b) accelerating toward the moon at 3.6 m/s^2? state the direction in each case.
[mass of moon: 7.36*10^22 kg]
[radius of moon: 1.74 * 10^6 m]
[Period...
I need help with a physics problem ASAP please :)
I am currently in AP Physics and we are studying centripetal force. My teacher gave me a problem that is driving me crazy because I don't know where to begin with it, and I have a test tomorrow...
Here's the problem:
An airplane pulls out...
An object hanging in the air causes a scale to read 0.0451kg. When the object was submerged in water, the scale is balanced at 0.0370. I found the object of the weight in air to be 0.442N. The question is to find the apparent weight when submerged in water. How do I find the volume to find...