Question

net force and acceleration quick check if multiple forces are acting on an object, which statement is always true? (1 point) the acceleration will be directed in the direction of the applied force. the acceleration will be directed in the direction of the gravitational force. the acceleration will be directed in the direction of the normal force. the acceleration will be directed in the direction of the net force.

Explanation:

To solve this, we use Newton's second law of motion, \( \vec{F}_{net} = m\vec{a} \), where \( \vec{F}_{net} \) is the net force, \( m \) is mass, and \( \vec{a} \) is acceleration. This law shows that acceleration is directly proportional to the net force and in the same direction as the net force.

• The first option is incorrect because "applied force" is not necessarily the net force (if multiple forces act, the net force is the vector sum, not just one applied force).
• The second option is incorrect because gravitational force is just one of many possible forces; the net force (which could include other forces like normal, friction, etc.) determines acceleration, not just gravity.
• The third option is incorrect because the normal force is also just one force (e.g., from a surface), and the net force (vector sum of all forces) determines acceleration, not just the normal force.
• The fourth option is correct because Newton's second law states that acceleration is in the direction of the net force (since \( \vec{a}=\frac{\vec{F}_{net}}{m} \), and mass \( m \) is a positive scalar, so the direction of \( \vec{a} \) matches \( \vec{F}_{net} \)).

Answer:

The acceleration will be directed in the direction of the net force.