A spring balance attched to the ceiling of an elevator supports a 10N object. In each of the following casses, tell whether there is a net force or none on the object. If there is in what direction does it act? Tell whether the reading in the spring balance in the following cases is less, equal or greater than the true weight of the object which is 10N

a. Elevator at rest

b. Moving with constant speed upward

c. Moving with constant speed downward

d. Moving upward with steadily increasing speed

e. moving downward with acceleration due to gravity

If you have ever been in an elevator you should be able to answer this. What forces are in play in each case? Imagine you standing on a weight scale in the elevator. What will the weight show in each case?

for a, b, and c, the only forces are the normal force and W which are equal soo there's no unbalanced force am i right

To determine whether there is a net force acting on the object in each case, we need to consider the forces acting on the object and their direction.

a. In this case, when the elevator is at rest, the object experiences only one force, which is its weight due to gravity. The force due to gravity acts in the downward direction, and the spring balance reading will be equal to the true weight of the object, which is 10N. Therefore, there is no net force on the object, and the reading on the spring balance will be equal to the true weight.

b. When the elevator is moving with constant speed upward, the object experiences two forces: its weight and the tension force from the spring balance. The weight due to gravity still acts in the downward direction, but the tension force from the spring balance counteracts it and acts in the upward direction. Since the object is moving with constant speed, the net force on the object is zero. The reading on the spring balance will be less than the true weight of the object since the tension force is reducing the effective weight of the object.

c. Similar to case b, when the elevator is moving with constant speed downward, the object experiences two forces: its weight and the tension force from the spring balance. The weight due to gravity still acts in the downward direction, and the tension force from the spring balance acts in the upward direction. Again, the net force on the object is zero, and the reading on the spring balance will be less than the true weight of the object.

d. When the elevator is moving upward with steadily increasing speed, the object experiences three forces: its weight, the tension force from the spring balance, and an additional force due to the acceleration of the elevator. The weight due to gravity and the tension force act in opposite directions, while the additional force due to the acceleration of the elevator acts in the upward direction. The net force on the object is the sum of the weight and the additional force. In this case, the net force is greater than zero, and the reading on the spring balance will be greater than the true weight of the object.

e. When the elevator is moving downward with acceleration due to gravity, the object experiences two forces: its weight and the tension force from the spring balance. The weight due to gravity acts in the downward direction, and the tension force acts in the upward direction. The net force on the object is the difference between the weight and the tension force. In this case, the net force is greater than zero in the downward direction, and the reading on the spring balance will be less than the true weight of the object.