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2 years ago

When fireworks explode, sound and light are produced. These are examples of

Physics

1 answer:

ki77a [65]2 years ago

6 0

Answer: Macroscoptic Output

Explanation:

Answers to the rest:

1. B) macroscopic outputs.

2.A) a microscopic change creating a macroscopic output

3.B) Because the energy levels of the electrons in different metals are usually not the same, different metals usually emit different colors of visible light.

4.A) Heat is applied to a solid, causing its molecules to move quickly.

5.A) strontium, sodium, copper, potassium

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A car manufacturer wants to change its car’s design to increase the car’s acceleration. Which changes should the engineers consi

likoan [24]

Answer:

The car manufacturers could increase bore of the cylinders, place the engine in the center or back of the car, add 1 to 2 turbochargers, and lower the center of gravity of the vehicle to increase traction.

Explanation:

Turbochargers would be recommended because they significantly increase both the torque of the engine as well as the amount of horses powering the car while also increasing original efficiency both with and without the additional power. Weight adjustment allows for lightweight vehicles with good traction. This is important to both keep control of the car under acceleration, but it also makes the vehicle more efficient due to the now sheddable unnecessary weight. A more obvious approach would be to increase the base horsepower and torque of the engine by increasing the bore of the cylinders and the weight of the pistons. This acts as an inertial lever, because the extra piston weight will drag the crankshaft faster. This could also be achieved by taking away piston weight, but this could be catastrophic should a piston slip.

4 0

3 years ago

Which of the following is one way that an electric motor's rotation speed can be controlled?

malfutka [58]

Depending on which type of motor you're talking about, but the first 3 are true. A stronger magnetic field in a DC motor will slow it down but increase its torque.
The amount of current in the motor will control the magnetic fields and therefore affect the speed (and torque). In an induction motor, the rotational speed is given by $n= \frac{120f}{p}$ where f is the line frequency and p is the number of poles. Thus fewer poles makes it go faster.

5 0

3 years ago

Read 2 more answers

AB and BA name the same ray

ICE Princess25 [194]

False. Ray AB starts at point A and continues through and infinity beyond point B. Ray BA is the reverse. in the name of a Ray the starting point always comes first.

8 0

3 years ago

Compare these two collisions of a PE student with a wall.

Stolb23 [73]

1) The variable that is different in the two cases is $\Delta t$ , the duration of the collision

2) The change in momentum is the same in the two cases

3) The impulse is the same in the two cases

4) Case B will experience a greater force

Explanation:

The variable that is different in the two cases is $\Delta t$ , the duration of the collision.

In fact, in the first case the wall is padded: this means that the collision will be "softer" and therefore will last longer, so the duration of the collision, $\Delta t$ , will be larger.

In the second case instead, the wall is unpadded: this means that the collision is "harder" and so it will last less time, therefore the duration of the collision $\Delta t$ will be smaller.

The change in momentum in the two cases is the same.

In fact, the change in momentum is given by:

$\Delta p = m(v-u)$

where:

m is the mass of the student

u is the initial velocity

v is the final velocity

In both cases, we have:

m = 75 kg

u = 8 m/s

v = 0 (they both comes to rest)

Therefore, the change in momentum is

$\Delta p = (75)(0-8)=-600 kg m/s$

The impulse in the two cases is the same.

In fact, impulse is defined as the product of force applied, F, and duration of the collision, $\Delta t$ :

$J=F \Delta t$

However, the force can be rewritten as product of mass (m) and acceleration (a), according to Newton's second law:

$F=ma$

So the impulse is

$J=ma\Delta t$

The acceleration can be rewritten as rate of change of velocity:

$a=\frac{\Delta v}{\Delta t}$

So the impulse becomes

$J=m\frac{\Delta v}{\Delta t}\Delta t = m\Delta v$

So, the impulse is equal to the change in momentum: and since in the two cases the change in momentum is the same, the impulse is the same as well.

The force in the collision is related to the impulse by

$J=F\Delta t$

where

J is the impulse

F is the force

$\Delta t$ is the duration of the collision

The equation can be rewritten as

$F=\frac{J}{\Delta t}$

In the two situations described in the problem (A and B), we already said that the impulse is the same (because the change in momentum is the same). However, in case A (padded wall) the time $\Delta t$ is longer, while in case B (unpadded wall) the time $\Delta t$ is shorter: since the force F is inversely proportional to the duration of the collision, this means that in case B the student will experience a greatest force compared to case A.

Learn more about impulse:

brainly.com/question/9484203

#LearnwithBrainly

3 0

3 years ago

Which of the following objects is an example of a luminous source?

Korvikt [17]

Answer:

B. Moon

Explanation:

In physics, that would be the answer.

7 0

2 years ago

Read 2 more answers