Question

physics inmotion gpb.org/physics - motion unit 2e free fall note - taking guide and questions to consider name: date: answer the following. 1. when an object is experiencing “free fall,” what is the only force acting upon it? 2. does the acceleration of a falling object depend on its mass? explain. 3. what is the rate of acceleration due to gravity on the earth? 4. in what direction does gravity always cause objects to accelerate? 5. if the initial velocity of an object is upward in the positive direction, what must the sign of the acceleration due to gravity be in a calculation? 6. a ball is thrown straight up in the air. a. at the peak of its ascent, what is it doing? b. what is the balls velocity at this point? c. what is the balls acceleration at this point?

Explanation:

1. In free - fall, ignoring air resistance, the only force is gravity.
2. According to Newton's second law \(F = ma\) and \(F=mg\), \(a = g\) (acceleration due to gravity), so acceleration of a falling object in free - fall does not depend on mass.
3. The acceleration due to gravity on Earth is approximately \(9.8\ m/s^{2}\) near the surface.
4. Gravity always causes objects to accelerate towards the center of the Earth (downward).
5. If upward is positive, acceleration due to gravity is negative as it acts downward.
6. a. At the peak of its ascent, the ball is changing direction from moving up to moving down.

b. At the peak, the ball's velocity is 0 m/s as it momentarily stops before falling back down.
c. The acceleration at the peak is still \( - 9.8\ m/s^{2}\) (due to gravity).

Answer:

1. Gravity
2. No. According to \(F = ma\) and \(F = mg\), \(a = g\) which is independent of mass.
3. Approximately \(9.8\ m/s^{2}\)
4. Downward (towards the center of the Earth)
5. Negative
6. a. Changing direction from upward to downward

b. 0 m/s
c. \(-9.8\ m/s^{2}\)