Open Question
(I) Sketch the free-body diagram of a baseball
(b) after it has left the bat and is flying toward the outfield. Ignore air resistance.
6. Intro to Forces (Dynamics)
Types Of Forces & Free Body Diagrams
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The figure shows all the forces acting on an object. What can you tell about the velocity of the object at this instant? 
A
The object is moving downwards.
B
The object is moving upwards.
C
The object is slowing down.
D
The object is speeding up.
E
By looking at the free body diagram we can tell the acceleration is downward, but this only tells us how the velocity is changing, it does not tell us anything about the magnitude or direction of the velocity at this instant.
Verified step by step guidance1
Examine the free body diagram: The diagram shows two forces, F1 pointing downward and F2 pointing upward, acting on the object.
Determine the net force: Calculate the net force by subtracting the upward force F2 from the downward force F1. This can be expressed as F_net = F1 - F2.
Analyze the direction of the net force: If F1 is greater than F2, the net force is downward. If F2 is greater than F1, the net force is upward.
Relate net force to acceleration: According to Newton's second law, F_net = m * a, where m is the mass of the object and a is its acceleration. The direction of the net force determines the direction of the acceleration.
Conclude about velocity: The acceleration indicates how the velocity is changing, not the current velocity. If the net force is downward, the object is accelerating downward, meaning its velocity is increasing in the downward direction or decreasing if it was initially moving upward.
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