A 72.0-kg person stands on a scale in an elevator. What is the apparent weight when the elevator is

(a) accelerating upward with an acceleration of 1.80 m/s2,
N
(b) moving upward at a constant speed, and
N
(c) accelerating downward with an acceleration of 1.30 m/s2?
N
I just need to know how to do these problems

W= mg +- mg + when going up, - when down.

W= mg +- ma + when a going up, - when down.

To solve these problems, you will need to use Newton's second law, which states that the net force acting on an object is equal to its mass multiplied by its acceleration.

First, we need to determine the normal force acting on the person in each scenario. The normal force is the force exerted by a surface to support the weight of an object resting on it. In this case, the normal force is equal to the apparent weight of the person.

(a) When the elevator is accelerating upward:
To determine the apparent weight, we need to consider the force acting on the person: the gravitational force (mg) and the net force (ma), where m is the mass of the person, g is the acceleration due to gravity (9.8 m/s^2), and a is the acceleration of the elevator.

The net force is the sum of the gravitational force and the force due to acceleration:
Net force = mg + ma

Substituting the given values, the equation becomes:
Net force = (72.0 kg)(9.8 m/s^2) + (72.0 kg)(1.80 m/s^2)

Calculating the numerical value of the net force will give you the apparent weight of the person.

(b) When the elevator is moving upward at a constant speed:
In this case, there is no acceleration, so the net force on the person is zero. The apparent weight is equal to the gravitational force only, which is mg.

Apparent weight = (72.0 kg)(9.8 m/s^2)

(c) When the elevator is accelerating downward:
Similar to part (a), the net force is the sum of the gravitational force and the force due to acceleration. However, in this case, the acceleration is in the opposite direction, so we subtract it from the gravitational force.

Net force = mg - ma

Substituting the given values, the equation becomes:
Net force = (72.0 kg)(9.8 m/s^2) - (72.0 kg)(1.30 m/s^2)

Calculating the numerical value of the net force will give you the apparent weight of the person.

Remember to convert the mass from kg to N using the equation 1 kg = 9.8 N.

To solve these problems, you need to understand the concept of apparent weight and how it differs from actual weight. The apparent weight is the force on an object experienced when it is in contact with a scale or a surface. It can differ from the actual weight of an object, which is the force exerted on an object due to gravity.

To calculate the apparent weight, you need to consider the forces acting on the person in each scenario:

(a) Accelerating upward with an acceleration of 1.80 m/s^2:
When the elevator is accelerating upward, the apparent weight will be greater than the actual weight. This is because there is an additional force acting on the person due to the acceleration.

To calculate the apparent weight, you can use Newton's second law: F = m*a, where F is the net force acting on the person, m is the mass of the person, and a is the acceleration.

Since the person is not moving vertically, the net force is equal to the apparent weight. Therefore, the equation becomes:
Apparent Weight = m * (g + a)

Substituting the given values:
Apparent Weight = 72.0 kg * (9.8 m/s^2 + 1.80 m/s^2)
Apparent Weight = 72.0 kg * 11.6 m/s^2
Apparent Weight = 835.2 N

Therefore, the apparent weight when the elevator is accelerating upward with an acceleration of 1.80 m/s^2 is 835.2 N.

(b) Moving upward at a constant speed:
When the elevator is moving upward at a constant speed, the apparent weight will be equal to the actual weight. This is because there is no acceleration acting on the person.

Therefore, the apparent weight will be the same as the actual weight, which is given by: Actual Weight = m * g.

Substituting the given values:
Actual Weight = 72.0 kg * 9.8 m/s^2
Actual Weight = 705.6 N

Therefore, the apparent weight when the elevator is moving upward at a constant speed is 705.6 N.

(c) Accelerating downward with an acceleration of 1.30 m/s^2:
When the elevator is accelerating downward, the apparent weight will be less than the actual weight. This is because the acceleration is in the opposite direction to the force due to gravity.

Using the same equation as in part (a), we have:
Apparent Weight = m * (g - a)

Substituting the given values:
Apparent Weight = 72.0 kg * (9.8 m/s^2 - 1.30 m/s^2)
Apparent Weight = 72.0 kg * 8.5 m/s^2
Apparent Weight = 612 N

Therefore, the apparent weight when the elevator is accelerating downward with an acceleration of 1.30 m/s^2 is 612 N.

Remember, the apparent weight can be calculated by considering the forces and using Newton's second law.