Question

when considering gravity acceleration and the force of acceleration, what must be true?
a) the mass of the body must be the same as the acceleration of the body.
b) the direction of acceleration must be perpendicular to the direction of the force.
c) the direction of the force and the direction of acceleration must be the same as each other.
d) the direction of the force and the direction of acceleration must be opposite of each other.

Explanation:

To solve this, we use Newton's second law, \( F = ma \), where \( F \) is force, \( m \) is mass, and \( a \) is acceleration. Mass and acceleration are different physical quantities (mass is a scalar related to inertia, acceleration is a vector related to velocity change), so option A is wrong. Newton's second law also tells us that the direction of the net force and the direction of acceleration are the same (since \( \vec{F} = m\vec{a} \), and mass \( m \) is a positive scalar, so the vectors \( \vec{F} \) and \( \vec{a} \) have the same direction). Thus, option B (perpendicular) and D (opposite) are wrong, and C is correct.

Answer:

C. The direction of the force and the direction of acceleration must be the same as each other.