Question

5 - 4 as the elevator approaches the second floor, it begins to slow to a stop. which choice properly describes her weight, contact force, and acceleration at this point?
○a. weight = 130 lbs downward, contact force = 130 lbs upward, acceleration is zero
○b. weight = 130 lbs downward, contact force = 130 lbs upward, acceleration is downward
○c. weight = 130 lbs downward, contact force = 130 lbs upward, acceleration is upward
○d. weight = 140 lbs downward, contact force = 130 lbs upward, acceleration is downward
○e. weight = 140 lbs downward, contact force = 130 lbs upward, acceleration is upward
○f. weight = 130 lbs downward, contact force = 120 lbs upward, acceleration is upward
○g. weight = 130 lbs downward, contact force = 120 lbs upward, acceleration is downward
5 - 5 a bullet is fired horizontally from a high - powered rifle. at the same time, a second bullet is simply dropped from the same height as the bullet which was fired from the rifle. neglecting air resistance, which statement is true about the acceleration of the first bullet after it leaves the gun compared to that of the second bullet as it falls?

Explanation:

Step1: Analyze weight

Weight is the force due to gravity acting on the person. It remains constant near the Earth's surface and acts downward. Given weight = 130 lbs downward.

Step2: Analyze contact - force and acceleration

As the elevator is slowing down (decelerating) while moving upward, the net force must be downward. According to Newton's second - law $F_{net}=ma$. The net force $F_{net}=mg - N$ (where $mg$ is weight and $N$ is the contact force). For the net force to be downward, the weight ($mg = 130$ lbs downward) must be greater than the contact force ($N$). Also, since the elevator is slowing down while moving upward, the acceleration is downward.

Answer:

G. weight = 130 lbs downward, contact force = 120 lbs upward, acceleration is downward