when a projectile is released, why is there a change in speed in one dimension but not the other?(1 point)
a) a projectile only moves in two dimensions because it is thrown.
b) a projectile only moves in one dimension.
c) the force of gravity only acts in a downward direction.
d) there can be only one force acting on an object at a time.
c) the force of gravity only acts in a downward direction.
c) the force of gravity only acts in a downward direction.
The correct answer is c) the force of gravity only acts in a downward direction.
When a projectile is released, such as a ball being thrown into the air, there is a change in speed in one dimension but not the other because of the force of gravity. Gravity only acts vertically downward, causing the projectile to accelerate downward at a constant rate. However, in the horizontal dimension, there is no force acting on the projectile to change its speed. This means that the projectile will continue to move horizontally at a constant speed, while its vertical speed changes due to the force of gravity pulling it downward.
To understand this concept, it is helpful to break down the motion of a projectile into its horizontal and vertical components. In the absence of any other forces, the horizontal component of a projectile's motion remains constant because there are no forces acting on it in that direction. This means that a projectile will continue to move forward at a constant speed horizontally unless acted upon by external forces such as air resistance.
On the other hand, the vertical component of a projectile's motion is affected by the force of gravity. Gravity pulls the projectile downwards, causing it to accelerate in the vertical direction. As a result, the speed of the projectile in the vertical dimension changes, increasing as it moves upward and decreasing as it falls back down.
So, it is the force of gravity acting only in the downward direction that causes a change in speed in one dimension (vertical) but not the other (horizontal) when a projectile is released.