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3 years ago

Help me please!! 15points

Physics

1 answer:

Romashka-Z-Leto [24]3 years ago

4 0

Explanation:

Acceleration is the change in speed over change in time.

a = Δv / Δt

a. The car's acceleration is:

a = (80 km/h − 0 km/h) / 10 s

a = 8 km/h/s

So every second, the speed increases by 8 km/h.

b. The cyclist's acceleration is:

a = (16 m/s − 4.0 m/s) / 5.6 s

a = 2.1 m/s²

c. The stone's speed is:

10.0 m/s² = (v − 0 m/s) / 3.5 s

v = 35 m/s

d. The time is:

1.6 m/s² = (10 m/s − 0 m/s) / t

t = 6.3 s

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Technician A says that a power-assisted brake system reduces stopping distances compared to a nonpower-assisted brake system. Te

yanalaym [24]

Answer:

Technician B

Explanation:

here on analyzing both the statements from technician A and technician B. The Statement from Technician B is more logical and correct. That the power-assisted brake system reduces the force that the driver must exert on the brake pedal.

The power-assisted brake system does not reduce the distance of stopping. What it does is it reduces the force to be applied by the driver. Thus, making the drive more comfortable.

4 0

3 years ago

A commuter train passes a passenger platform at a constant speed of 40.4 m/s. The train horn is sounded at its characteristic fr

mihalych1998 [28]

(a) -83.6 Hz

Due to the Doppler effect, the frequency of the sound of the train horn appears shifted to the observer at rest, according to the formula:

$f' = (\frac{v}{v\pm v_s})f$

where

f' is the apparent frequency

v = 343 m/s is the speed of sound

$v_s$ is the velocity of the source of the sound (positive if the source is moving away from the observer, negative if it is moving towards the observer)

f is the original frequency of the sound

Here we have

f = 350 Hz

When the train is approaching, we have

$v_s = -40.4 m/s$

So the frequency heard by the observer on the platform is

$f' = (\frac{343 m/s}{343 m/s - 40.4 m/s})(350 Hz)=396.7 Hz$

When the train has passed the platform, we have

$v_s = +40.4 m/s$

So the frequency heard by the observer on the platform is

$f' = (\frac{343 m/s}{343 m/s + 40.4 m/s})(350 Hz)=313.1 Hz$

Therefore the overall shift in frequency is

$\Delta f = 313.1 Hz - 396.7 Hz = -83.6 Hz$

And the negative sign means the frequency has decreased.

(b) 0.865 m

The wavelength and the frequency of a wave are related by the equation

$v=\lambda f$

where

v is the speed of the wave

$\lambda$ is the wavelength

f is the frequency

When the train is approaching the platform, we have

v = 343 m/s (speed of sound)

f = f' = 396.7 Hz (apparent frequency)

Therefore the wavelength detected by a person on the platform is

$\lambda' = \frac{v}{f'}=\frac{343 m/s}{396.7 Hz}=0.865m$

5 0

3 years ago

Now consider a wave which is paired with seven other waves into seven pairs. The two waves in each pairing are identical, except

kupik [55]

The pair BCEG will interfere constructively, while the pair ADF will interfere destructively.

Constructive and destructive interference:

For interference, the waves must be coherent.

Two coherent waves interfere constructively when the path difference is equal to an integral multiple of the wavelength.

That is the path difference must be mλ

where m = 0,1,2,3.... is an integer and λ is the wavelength

So pair BCEG interfere constructively

Two coherent waves interfere destructively when the path difference is equal to a half-integral multiple of the wavelength.

That is the path difference must be (m+1/2)λ

where m = 0,1,2,3.... is an integer and λ is the wavelength

Therefore, the interference is in the pair ADF which is interfere destructively.

Learn more about interference: brainly.com/question/1194044

#SPJ4

[NOTE: THE COMPLETE QUESTION IS:

Now consider a wave which is paired with seven other waves into seven pairs. The two waves in each pairing are identical, except that one of them is shifted relative to the other in the pair by the distance shown: A. -(1/2) ?B. 2?C. -5?D. (3/2)?E. 0F. (17/2)?G. (6/2)?Identify which of the seven pairs will interfere constructively and which will interfere destructively. Each letter represents a pair of waves. Enter the letters of the pairs that correspond to constructive interference in alphabetical order and the letters of the pairs that correspond to pairs that interfere destructively in alphabetical order separated by a comma. For example if pairs A, B and D interfere constructively and pairs C and F interfere destructively enter ABD,CF.]

4 0

1 year ago

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Is this true or false a seismograph records the air movements caused by sseismic waves

olasank [31]

The answer to this question is False.

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3 years ago

If a person climbed Mt. Everest has a mass of 105 kg and a weight of 625 N what would be the acceleration due to gravity?

DanielleElmas [232]

The acceleration due to gravity would be 5.95 m/s²

A force is known to be a push or pull and it is the change in momentum per time. It can be expressed by using the relation.