A pencil is dropped from inside an elevator moving 5m/s upward. Calulate the time it takes to drop from 1m to elevator floor and its velocity.
I approached as a velosy problem. Is this more of a Force problem ? I could calculate the velocity and time it took while the elevator was at a...
Homework Statement
this should be simple question, but i could not get the answer. hope someone could point out my mistake.
A person stands on a scale in an elevator. As the elevator starts, the scale has a constant reading of 587 N. Later, as the elevator later stops, the scale reading is...
Homework Statement
Based on the trends in your data, predict how riding an elevator while standing on a scale will affect your weight measurement. Try it and describe the forces on you.
Homework Equations
It's a philosophical question; no math needed.
The Attempt at a Solution
I did...
Homework Statement
A bolt comes loose from the bottom of an elevator that is moving upward at a speed of 6.88 m/s. The bolt reaches the bottom of the elevator shaft in 3.90 s. How high up was the elevator when the bolt came loose?
Homework Equations
d= v(initial)t + .5at^2
The...
Is a falling elevator a valid inertial frame?
The title about says it. Is a body, (frame) free falling in a gravitational field a valid inertial frame as defined by SR?
Thanks
Homework Statement
An inclined plane, fixed to the inside of an elevator, makes a 40 angle with the floor. A mass m slides on the plane without friction. What is the acceleration relative to the block if the elevator is a)accelerating upwards .35g b)accelerating downwards .35g? c)constant...
1)A student weighing 735 N steps into an elevator and pushes the button to go up. If the elevator accelerates at 3.5 m/s2 for 3.0 s, what is the mass of the student during this time?
2)f=ma, v=d/t
3)i don't quite understand how the student can weigh 735 N and consequently I'm...
Need help:Weighing yourself in the elevator-acceleration problem
Homework Statement
If you stand on a spring scale in your bathroom at home, it reads 600N, which means your mass is 60kg. If instead, you stand on the scale while accelerating at 2 m/s^2 upward in an elevator, what would the...
Homework Statement
the question given is:
What would the reading on a bathroom scale be if a 60kg pupil was accelerated upwards at a rate of 3m.s-2
Homework Equations
F=m(g-a)
F=ma
The Attempt at a Solution
F=m(g-a)
F=60kg(10m.s-2-3m.s-2)
F=600-180
F=420N which is...
Space Elevator
Your first job after graduation you are hired by a engineering firm that just got a contract to build the first space elevator. The space elevator consists of a cable hanging from geo-stationary satellite to an anchor point on earth’s surface. Once installed this equipment can...
Homework Statement
Question: An Elevator and its load have a mass of 1200 kg.
a) what energy must be supplied to lif the elevator and its load ot a height of 100m? Answer: E = _________ Joules
b)If the elevator rises at a speed of 5 m/s, how long does it take to cover 100m? Answer t=...
Hello, I'm currently studying for the mcat and ran across this problem in one of my practice tests.
An elevator used in a building has a mass of 1000 kg when empty
the elevator hangs on a single cable
step 1. the elevator rises for 2m/s^2 for 3 seconds,
if there is no friction on the...
Homework Statement
I am planning a lab where I am investigating the (inversely proportional) relationship between the velocity at which an elevator is moving and the mass inside an elevator.
Method:
1. Estimating distance the elevator is going to travel.
2. Have a mass of 100 kg inside the...
Hi there,
i am making an elevator design driven by a microcontroller. i am an electronics student and hence i am not able to get the mechanical design aspect of the elevator.
can anyone explain to me how to design the mechanical aspect of the elevator? what are the components for braking...
Homework Statement
A 192 lb person stands on a scale in an elevator. What does the scale read
a. When the elevator is at rest.
b. when the elevator is accelerating up at 4ft/sec^2
c. when elevator is accelerating down at 3ft/sec^2
Homework Equations
The Attempt at a Solution...
Alright, so I'm a little stuck on the last bit of this problem:
The cable of the 1,800 kg elevator cab snaps when the cab is at rest at the first floor, where the cab bottom is a distance d = 3.7 m above a cushioning spring whose spring constant is k = 0.15 MN/m. A safety device clamps the cab...
Homework Statement
You are standing on the floor of an elevator that starts, at rest, at the first floor of a building and then moves at constant speed to the tenth floor where it stops. Then you reverse the motion, ending where you started at the first floor.
Describe the two important forces...
Homework Statement
The figures depict situations where a person is standing on a scale in eight identical elevators. Each person weighs 600 N when the elevators are stationary. Each elevator now moves (accelerates) according to the specified arrow that is drawn next to it. In all cases where...
Homework Statement
A simple Pendulum is suspended from the ceiling of an elevator. The elevator is accelerating upwards with acceleration a. The period of this pendulum, in terms of its length L, g, and a is:
2\pi*(L/a)^(1/2)
OR
2\pi*(L/(g+a))^(1/2)
OR
2\pi*(L/g)^(1/2)
Homework...
a 71 kg man is standing in an elevator on a scale. the elevator is traveling up with an acceleration of 3 m/s^2. what does the scale read the weight of the man as?
thanks guys!
Homework Statement
An elevator weighing 2.00 X10^5 N is supported by a steel cable. What is the tension in the cable when the elevator is accelerated upward at a rate of 3.00m/s^2? (g=9.81m/s^2)
Homework Equations
I realize this is probably a very simple problem, but neither my textbook...
Homework Statement
A 3.0-kg lamp is suspended by a wire from the ceiling of an elevator. What can you conclude about the
tension in the wire under each of the following circumstances? (Give a numerical result, or a range of possible
numerical results, or if you can’t conclude anything...
Homework Statement
Using the usual angle \phi, as generalized coordinate, write down the Lagrangian for a simple pendulum of length l suspended from the ceiling of an elevator that is accelerating upward with constant acceleration a. Find the Lagrangian equation of motion and sho that it is...
Homework Statement
An elevator motor which is 60% efficient uses 80kW of power while lifting a 2000kg elevator 30m. If the elevator contains five passengers of the same mass and it takes 15 seconds to accomplish this task, then determine the mass of each passenger.Homework Equations...
Homework Statement
A 1200kg elevator driven by an electric motor can safely carry a maximum load of 800kg. What is the power provided by the motor when the elevator ascends with a full load at a speed of 2.3 m/s
Homework Equations
P=F*v
The Attempt at a Solution
So I use directly...
Homework Statement
In a 'worst-case' design scenario a 2000-kg elevator with broken cables is falling at 25m/s when it first contacts a cushioning spring at the bottom of the shaft. The spring is supposed to stop the elevator, compressing 3m as it does so. During the motion, a safety clamp...
The tension on a string from which a 4.0 kg object is suspended in an elevator is equal to 44.0 Newton.
What is the acceleration of the elevator?
Is this answer rigth
44 N - (4.0 kg X 9.8) = a (4.5 + 4) I think the 4.5 is mass of elevator and 4 the mass of the object which is...
Homework Statement
A rude tourist throws a peach pit horizontally with a 7.0 m/s velocity out of an elevator cage.
(a) If the elevator is not moving, how long will the pit take to reach the ground, 11.0 m below?
s
(b) How far (horizontally) from the elevator will the pit land?
m
(c)...
1. Mass is hung from a force probe, with negative force calibrated as down. The mass is 0.5 kg, the height of each floor is 5 m, and v0 = a0 = 0. Assume that I start on the 6th floor, what floors did I stop on, and how long was I on each floor?
2. I was wondering, how would one find the position...
Homework Statement
A woman stands on a scale in a moving elevator. Her mass is 60.0 kg, and the combined mass of the elevator and scale is an additional 815 kg. Starting from rest, the elevator accelerated upward. During the acceleration, the hoisting cable applies a force of 9410 N. What...
Homework Statement
one day you take your bathroom scale with you into an elevator. the scale reads 150 lbs as the door closes. the reading varies between 120 lbs and 170 lbs as the elevator travels up. what is the acceleration of the elevator while its accelerating and decelerating...
Homework Statement
A 500 kg elevator starts from rest. It moves upward for 3.50 s with constant acceleration until it reaches its cruising speed, 1.75 m/s.
(a) What is the average power of the elevator motor during this period?
(b) How does this power compare with the motor power when the...
Homework Statement
A 80.0 kg person stands on a scale in an elevator.
(c) What does it read when the elevator is falling at 3.5 m/s?
Homework Equations
EF = MA
The Attempt at a Solution
I can't even attempt the solution because I don't know acceleration...
I'm having trouble with this problem:
A 80.0 kg person stands on a scale in an elevator.
(e) What does it read when the elevator is accelerating downward at 3.5 m/s2? In KG
I set it up as EF = ma , but it doesn't work out...
EF = MA
Move objects inside elevator...
Homework Statement
You are moving a large crate from the back of the freight of the elevator to the front as the elevator is moving to the next floor.In which situation is the force you must apply to move the crate the smallest and in which is it the largest...
Homework Statement
An elevator has a mass of 956 kg and car-
ries a maximum load of 764 kg. A constant
frictional force of 4150 N retards its motion
upward.
The acceleration of gravity is 9.8 m/s2 .
What power must the motor deliver at a
instantaneous speed of 4.69m/s if the elevator
is...
Homework Statement
An object weighs 65 kg. When it is in an elevator on a bathroom scale, the scale reads 82 kg. What is the acceleration of the elevator and what is its direction?
Homework Equations
FG = mg
The Attempt at a Solution
(82 kg)(9.8) = 803.6 N
803.6 N = (65...
Hello guys, I am currently busy with this introductory assignment on Newtons Laws.
I have tried to solve but i am not sure whether i have the right solution.
Please help.
Homework Statement
Three blocks are stacked on top of each other inside an elevator as shown in the figure.
Answer...
Homework Statement
For this problem I need to figure out how weight changes in a moving elevator. So for example if I had a 20lb dumbbell on a scale and went up 3 floors would the actual weight of the dumbbell change? How would this show on the scale. Then I have the same question except...
Homework Statement
A woman stands on a scale in a moving elevator. Her mass is 58.5 kg, and the combined mass of the elevator and scale is an additional 815 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force of 9510 N. What does...
Homework Statement
Normal mass is 65kg. I get into an elevator, on a scale in the elevator and it reads 76 kg. Find a along with direction.Homework Equations
w = mg + ma
The Attempt at a Solution
Obviously the elevator is accelerating upwards due to the apparent increase in mass...
I'm having a hard time with this question, I've done my share of research/computation and came up with an answer. Though I don't think the answer is correct and it might not even be what the question is asking for. Please help me out, thanks in advance!
Weight in an Accelerating Elevator...
Homework Statement
In a "worst-case" design scenario, a 2000-kg elevator with broken cables is falling at 4.00 m/s when it first contacts a cushioning spring at the bottom of the shaft. The spring is supposed to stop the elevator, compressing 2.00 m as it does so. During the motion a safety...
Homework Statement
You are riding in an elevator on the way to the eighteenth floor of your dormitory. The elevator's upward acceleration is a= 1.84 . Beside you is the box containing your new computer; box and contents have a total mass of 28.9 kg. While the elevator is accelerating upward...
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
While riding on an elevator descending with a constant speed of 3.3 m/s, you accidentally drop a book from under your arm.
(a) How long does it take for the book to reach the elevator floor, 1.1 m below your arm?
s
(b) What is the book's speed (relative to the earth)...
I think there has been floated the idea that the space elevator tether may be a ribbon. I think it will fail if it isn't round. I think it will twist with the wind, it will twist in different directions at different altitudes, the twisting will change it's length dramatically and it will break...
Homework Statement
An inclined plane, fixed to the inside of an elevator, makes a 25 angle with the floor. A mass m slides on the plane without friction. What is the acceleration relative to the block if the elevator is a)accelerating upwards .35g b)accelerating downwards .35g? c)constant...
Homework Statement
A person with a weight of 500N stands in an elevator on a scale.
from 0-5s his weight reads 500N.
from 5-10s his weight reads 700N.
from 10-15s his weight reads 500N.
from 15-20s his weight reads 300N.
Find his acceleration (in each time interval) and his velocity...
Homework Statement
While an elevator of mass 2442 kg moves upward, the tension in the cable is 34.2 kN
Homework Equations
(a) What is the ?
(a) What is the acceleration of the elevator?
The Attempt at a Solution
a= f/m
a= 34200N/2442kg =14.0