Answer:
Speed- 48m/s..........................................
Answer:
The medium for the sound waves produced by the dog barking is the air
Explanation:
Sound waves are a form of mechanical waves such that it moves from one point to another by the vibration, back and forth of the medium particles from one layer to the next, thereby the particles of the medium remain in the same location and only the wave energy is propagated
The medium which has particles that vibrate back and forth in order to transmit the barking of the dog is the air.
The net force acting on the two (2) kids is equal to 180 Newton.
<u>Given the following data:</u>
- Mass of kid 1 = 40 kilogram.
- Mass of kid 2 = 50 kilogram.
- Acceleration = 2

To determine the net force acting on the two (2) kids:
First of all, we would calculate the total mass of the two (2) kids:

Total mass = 90 kg.
<h3>
How to calculate net force.</h3>
In this exercise, you're required to calculate the magnitude of the net force that is acting on these two (2) kids running down the hall. Thus, we would apply Newton's Second Law of Motion.
Mathematically, Newton's Second Law of Motion is given by this formula;

Substituting the given parameters into the formula, we have;

Net force = 180 Newton.
Read more on acceleration here: brainly.com/question/1121817
Answer:
6.875 m/s
Explanation:
The force is variable which is given by
F(x) = 18 - 0.53 x
mass of the box, m = 8.9 kg
initially it is at rest at x = 0
Let the velocity is v after travelling a distance of 15 m.
According to the work energy theorem, the work done by all the forces is equal to the change in kinetic energy of the body.
Work done = change in kinetic energy



18 x 15 - 0.265 x 15 x 15 = 4.45 x v²
270 - 59.625 = 4.45 v²
v² = 47.275
v = 6.875 m/s
Thus, the final velocity of the box is 6.875 m/s.
Answer:Correct answer: 15.85 kg·m/s
Explanation:
A 30 kg gun is standing on a frictionless sur-face. The gun fires a 50 g bullet with a muzzlevelocity of 317 m/s.The positive direction is that of the bullet.Calculate the momentum of the bullet im-mediately after the gun was fired.