Question

The net force on an object in the positive x direction. Consider the following statements:

i) The object can be moving in the negative x direction.
ii) The object can be speeding up.
iii) The object can be slowing down.
iv) The object can be moving in the positive y direction.

Which of the statements are true?
(I tried ii and iii but the computer told me that was wrong)

Answer 1

The net force on an object in the positive x direction can cause it to move in the negative x direction or slow down, but not speed up. The net force does not affect the object's motion in the y direction.

Step-by-step explanation:

The net force on an object in the positive x direction can have certain effects on the object's motion. Let's analyze each statement:

i) The object can be moving in the negative x direction. True: The net force on an object can act in the positive x direction but the object can still move in the negative x direction if there is another force opposing the net force.

ii) The object can be speeding up. False: If the object is already moving in the positive x direction, applying a net force in the same direction will maintain its current speed, not speed it up.

iii) The object can be slowing down. True: If the object is already moving in the positive x direction, applying a net force in the opposite direction can slow it down or eventually stop it.

iv) The object can be moving in the positive y direction. False: The net force is specified to act in the positive x direction, so it does not affect the object's motion in the y direction.

Answer 2

An object under a net force in the positive x direction can move in the negative x direction (if decelerating) and can move in the positive y direction (since x and y motions are independent). However, it cannot be slowing down if it's already moving in the positive x direction, only speeding up. So the correct options are (i), (ii) and (iii).

Step-by-step explanation:

When analyzing the statements about the net force acting on an object, we use Newton's Second Law, which states that the acceleration of an object is in the same direction as the net force acting on it. An object moving in the positive x direction can be moving in the negative x direction if it is decelerating. It can also be moving in the positive y direction because motions in perpendicular directions do not affect each other.

Considering these details, the correct statements are:

1. The object can be moving in the negative x direction, as long as it is experiencing deceleration.
2. The object can be speeding up if it was initially at rest or moving in the positive x direction.
3. The object can be moving in the positive y direction because the x and y motions are independent of each other.

An object cannot be slowing down if the net force is in the same direction as its motion. Thus, the statement that the object can be slowing down is incorrect if the net force is in the positive x direction and the object is also moving in that direction, as it would be speeding up instead.