A. A car moving at a constant speed on a flat, straight road. B. A vehicle traveling at a steady speed on a 10-degree incline. An object operates within an inertial reference frame if there is no net force acting upon it. According to Newton's second law, this implies that the object's acceleration also equals zero. Assessing the scenarios yields: A. A car moving at a constant speed on a flat road qualifies as an inertial reference frame, since its velocity and direction remain unchanged; thus, acceleration is zero. B. A car moving steadily up a 10-degree incline still constitutes an inertial reference frame, for similar reasons. C. A car accelerating after departing a stop sign does not represent an inertial frame due to its change in speed. D. A car driving at a steady speed around a curve cannot be considered an inertial reference frame since its direction is changing, resulting in a change in velocity and thus acceleration. Therefore, options A and B are correct.
Answer:
17.35 × 10^(-6) m
Explanation:
Mass; m = 50 kg
Weight; W = 554 N
From the formula:
W = mg
This simplifies to; 554 = 50g
g = 554/50
g = 11.08 m/s²
Also, using the formula;
mg = GMm/r²
hence; g = GM/r²
Rearranging gives;
r = √(GM/g)
With G as a known constant of 6.67 × 10^(-11) Nm²/kg²
r = √(6.67 × 10^(-11) × 50/11.08)
r = 17.35 × 10^(-6) m
Conclusion:
The total net force acting on the objects is 16 N, directed towards the right.
Clarification:
It is stated that,
The force exerted by the dog,
(to the right)
The force exerted by Simone,
(backward)
Here, assume the backward direction is negative and the right direction is positive.
The net force will move in the direction where the larger force is present. The net force can be calculated as:


F = 16 N
Thus, the net force amounts to 16 N, acting towards the right.
Let's consider a few possibilities.
1. The lowest velocity of the paratrooper would be just before hitting the ground.
2. Given that the jump originated from a relatively short height, the paratrooper utilized a static line, allowing the parachute to deploy almost instantly after leaping.
Hence, we will convert 100 mi/h to ft/s:
100 mi/h * 5280 ft/mi / 3600 s/h = 146.67 ft/sec.
Based on the first assumption, the maximum distance fallen by the paratrooper would equate to 8 seconds at 146.67 ft/s, translating to
8 s * 146.67 ft/s = 1173.36 ft.
This calculated distance is nearly on par with the jump height, validating both assumptions 1 and 2. Thus, this scenario seems plausible.
Moreover, considering the terminal velocity for a parachutist in a freefall position with limbs spread out typically reaches 120 mi/h, which is slightly above the 100 mi/h mentioned in the article. This as well aligns with the notion of the parachute acting like a flag, adding some air resistance.
Answer:
d) v1 = v2 = v3
Explanation:
This can be determined through the principle of energy conservation. We assess the total mechanical energy E=K+U (the sum of kinetic energy and gravitational potential energy) at both the initial and final positions, ensuring they remain constant.
<pInitially, for the three spheres, we have:

Finally, for the three spheres, we see:

<pGiven that

, and since

remains identical for all spheres, it follows that

is identical for all spheres, indicating that

, the final velocity, is equal for each ball.