If you stand on a scale in an elevator accelerating upward, you feel heavier because the elevator’s floor presses harder on your feet, and the scale will show a higher reading than when the elevator is at rest. On the other hand, when the elevator accelerates downward, you feel lighter.
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How do you solve an elevator problem in physics?
support force F = mass x acceleration + weight For a mass m= kg, the elevator must support its weight = mg = Newtons to hold it up at rest. If the acceleration is a= m/s² then a net force= Newtons is required to accelerate the mass. This requires a support force of F= Newtons.
What force does a scale measure in an elevator?
The scale reads the Normal force, so it reports your weight as greater than it was at rest. The same two forces are at work as when the elevator was accelerating up. The scale will read the Normal force which is less than it was at rest.
How do you find the weight of an object in an elevator?
Does a scale measure normal force?
The scale measures the normal force because the force on the object and the normal force are necessarily equal in magnitude, through Newton III. The normal force is generally a proxy for mass, since it is often the sole force responsible for countering gravity when an object is at static equilibrium.
Why do you feel lighter when an elevator goes down physics?
This can also make you feel lighter: when the elevator slows down, you need to slow down with it. But gravity is always pulling you down, so for you to slow down, the floor needs to push up on you less, so gravity can slow you down. Since the floor pushes on you less, you feel lighter.
What will the scale read when the elevator is accelerating downward?
If the elevator accelerates downward, a is negative, and the apparent weight is less than the true weight. If the elevator falls freely, , and the apparent weight is zero.
Is the reading on the scale in the elevator higher/lower or the same as the reading in her bathroom?
When the elevator (you) moves up – acceleration increases (adding on to the 9.8ms2 ) and there is more normal force applied to the floor. This results in a larger number on the scale.
How do elevators work physics?
What will happen to a person’s weight when he is in a moving elevator?
From the above explanation and given condition when person in an elevator is moving at constant speed in such case the net acceleration will be zero. Thus we can say that person’s weight when he is in a moving elevator will not change because the apparent weight of the person will be equal to its true weight.
How much force is needed to lift a 25 kg?
(Note: The weight of a 25-kg object is approximately 250 N; it takes 250 N to lift the object up.)
How do you calculate the normal force of an elevator?
Consider the normal force acting on you from the elevator: N = mg if the elevator is at rest or moving at constant velocity. N = mg + ma if the elevator has an upward acceleration. N = mg – ma if the elevator has a downward acceleration.
What is the formula for weight in physics?
The weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity, w = mg.
What is the formula for apparent weight?
The apparent weight of an accelerating object is the vector sum of its real weight and the negative of all the forces that produce the object’s acceleration a = dv/dt. wapparent = wreal – ma.
What is the apparent weight felt by a person in an elevator?
R = m(g – g) = 0. Thus, the apparent weight of the man becomes zero. This is because both the man and the lift are moving downwards with same acceleration ‘g’ and so there are no forces of action and reaction between the person and the lift.
Does a scale read force or pressure?
Does a scale read force or pressure? The scale will read the same value if you lift up one foot. The scale reads force not pressure. When you lift one foot, less area in contact with the scale and thus the pressure on the scale has increased but the force is still the same scale.
What does a scale read physics?
If it’s a scale like a bathroom scale, it essentially gives you a measure of the force pressing against it. The reading itself could be a weight or a mass, since they are proportional.
Do scales measure in Newtons?
In the scale, this change in spring length is used to move a dial which indicates the force from your weight acting on the spring. We measure force in the unit known as a newton. So your scale should display your weight in newtons.
What happens to your weight when you are in a lift which goes down?
When the lift goes down the weight of the body decreases because when the lift goes down there is a force called pseudo force which pushes lift upward and results in a decrease in weight.
Why does a weight feel heavier at the beginning of the lift?
Once the elevator begins accelerating upward, it is not only supporting your weight but also pushing upward into your feet in order to accelerate your body upward with it.
Why does the weight of a body in the lift become zero when its cable breaks?
Solution : If the cable of the lift breaks suddenly the weight of the man would become zero because the system would all begin to accelerate downward due to the force of gravity. All objects in the freefall accelerate downward with the same magnitude.
When an elevator moves upward with a constant speed your weight reading on a scale is?
Understanding Normal Force : Example Question #2 Explanation: The normal force of the woman is measured by the scale. While accelerating upward, the scale should read a larger weight than when it is at rest. When the elevator is moving upward at a constant speed, the scale should read the same as when it is at rest.
When a lift is accelerating upwards?
N = mg if the elevator is at rest or moving at constant velocity. N = mg + ma if the elevator has an upward acceleration. N = mg – ma if the elevator has a downward acceleration.
Why might an elevator cable break during acceleration when lifting a lighter load than it normally supports at rest or at constant velocity?
In this acceleration range, the rope tension can increase in the range of 20% to 30% for typical acceleration values and according to equation (1). For this reason, the cable may break during acceleration even though it is carrying a lower load.
When you stand on a bathroom scale what force magnitude does the scale read?
Answer and Explanation: When a person stands on the bathroom scale in this position the person is in mechanical equilibrium and is at rest. Thus the net force on the person is zero.