Find the acceleration of the elevator.

In summary, to find the acceleration of the elevator, you can use the equation F=ma and subtract the person's weight from the normal force experienced in the elevator. This will give you the net force, which can be divided by the mass of the person to find the acceleration.
  • #1
badboyben03
39
0
how can i find the answer w/o knowing the mass?

A student stands on a bathroom scale in an elevator at rest on the 64th floor of a building. The scale reads 818 N. As the elevator moves up, the scale reading increases to 950 N, then decreases back to 818 N. Find the acceleration of the elevator.
 
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  • #2
Actually you can solve for the mass of the person when he is at rest. At rest, acceleration is due to gravity so:

[tex]F_{1}=mg[/tex]
and
[tex]m=\frac{F_{1}}{g}[/tex]

where [tex]g=9.81\frac{m}{s^2}[/tex] and [tex]F_{1}=818N[/tex].
 
  • #3
after i find the mass of the person? wut do i have to do?
 
  • #4
950N is the normal force the person experiences.

The person's weight must be subtracted out to get the net force which is 950N-818N=132N.

Using Newton's 2nd Law, we can can find the acceleration.

[tex]F=ma[/tex]

implies

[tex]a=\frac{F}{m}[/tex]

where F =132N and m is the mass of the person found.
 

1. What is acceleration?

Acceleration is the rate of change of velocity. In other words, it is the measure of how quickly an object's velocity is changing over time.

2. How is acceleration calculated?

Acceleration can be calculated by dividing the change in velocity by the change in time. The formula is a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

3. How does acceleration affect an object's motion?

Acceleration can affect an object's motion by changing its velocity. If the acceleration is positive, the object's velocity will increase. If the acceleration is negative, the object's velocity will decrease. Acceleration can also change the direction of motion.

4. How does gravity play a role in acceleration?

Gravity can cause acceleration on objects. When an object is in free fall, gravity is the only force acting on it and it accelerates at a rate of 9.8 m/s² towards the ground. This is known as the acceleration due to gravity.

5. How is acceleration related to Newton's laws of motion?

Acceleration is closely related to Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. In other words, the larger the force acting on an object, the greater its acceleration will be. This is why we can calculate the acceleration of the elevator by determining the net force acting on it and its mass.

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