Can anyone please help me with answering this? : A person of mass 75 kg stands on a scale inside an elevator. What can you infer about the motion of the elevator if the scale reads 735N and 900N?
his weight is ... 75 * g
if the scale reads his "correct" weight , the elevator is not accelerating
... if it reads less , the elevator is accelerating downward
... if it reads more , the elevator is accelerating upward
To understand the motion of the elevator, we need to analyze the forces acting on the person inside the elevator.
When the scale reads 735N, it means that the normal force acting on the person is equal to 735N. The normal force is the force exerted by a surface to support the weight of an object resting on it. In this case, the scale is providing the normal force.
The weight of the person is given by the formula:
Weight = mass × acceleration due to gravity
where the acceleration due to gravity is approximately 9.8 m/s².
When the scale reads 735N, it means the normal force is equal to the weight of the person. So we can calculate the weight of the person:
Weight = mass × acceleration due to gravity
735N = 75 kg × 9.8 m/s²
Solving for the mass:
mass = 735N / (9.8 m/s²) = 75 kg
This means that the elevator is in a state of equilibrium or is stationary. The scale is providing a normal force equal to the weight of the person, supporting them.
Now let's consider the second scenario when the scale reads 900N. In this case, the normal force provided by the scale is greater than the weight of the person.
Again, using the formula for weight:
Weight = mass × acceleration due to gravity
900N = 75 kg × 9.8 m/s²
Solving for the mass:
mass = 900N / (9.8 m/s²) = 91.8 kg
Here, the normal force exceeds the weight of the person, indicating that an additional force is acting on the person. In this scenario, the elevator is accelerating upward because the normal force is greater than the weight.
Therefore, we can infer that when the scale reads 735N, the elevator is stationary or in a state of equilibrium, and when the scale reads 900N, the elevator is accelerating upward.