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3 years ago

A sprinter who is running a 200-m race travels the second 100 m in much less time than the first 100m because

Physics

2 answers:

chubhunter [2.5K]3 years ago

4 0

Answer:

The sprinter must overcome inertia and accelerate during the first 100 m.

Harrizon [31]3 years ago

3 0

Answer:

He is warmed up now

Explanation:

His muscles are better and stretched now

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A certain type of bird lives in two regions of a state. The distribution of weight for birds of this type in the northern region

Annette [7]

Answer: (a) Z-score are 1 and -1.2 for northern and southern regions, respectively.

Explanation: <u>Z-score</u> is how many standard deviations a data is from the population mean or how far a data point is from the mean.

The z-score is calculated by the following:

$z=\frac{x-\mu}{\sigma}$

where

x is the data point

μ is population mean

σ is standard deviation

For the <u>northern</u> <u>region</u> birds:

μ = 10, σ = 3, x = 13

$z=\frac{13-10}{3}$

z = 1

The z-score for birds living in the northern region is 1, which means it is 1 standard deviation <em>above the mean</em>.

For the southern region:

μ = 16, σ = 2.5, x = 13

$z=\frac{13-16}{2.5}$

z = -1.2

The z-score for southern living birds is -1.2, meaning it is 1.2 standard deviations <em>below the mean</em>.

6 0

3 years ago

a 2000 kg truck is moving eastward at 25 m/s. it collides inelastically with a 1500 kg truck traveling southward at 30 m/s. they

Otrada [13]

According to the given statement Final velocity when they stick together is 8.735i^ + 11.25j^

<h3>What is collision and momentum?</h3>

The unit of momentum is kg ms -1. Momentum is a vector parameter that is influenced by the object's direction. During collisions involving objects, momentum is a relevant concept. The final velocity before a collision between two objects equals the total motion after the impact (in the absence of external forces).

<h3>Briefing:</h3>

From conservation of momentum

Initial momentum = final momentum

m u +M U =(m+M) V

2000×25 i^ +1500×30 j^ =(2000+1500) V

V = 8.735i^ + 11.25j^

Final velocity when they stick together is 8.735i^ + 11.25j^

To know more about Collide visit:

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The complete question is -

A 2000 kg truck is moving eastward at 25 m/s. it collides inelastically with a 1500 kg truck traveling southward at 30 m/s. they collide at the intersection. Find the direction and magnitude of velocity of the wreckage after the collision, assuming the vehicles stick together after the collision.

6 0

1 year ago

Two identical loudspeakers are placed on a wall 1.00 m apart. A listener stands 4.00 m from the wall directly in front of one of

natita [175]

Answer:

The phase difference is 0.659 rad.

Explanation:

Given that,

Distance between two identical loudspeakers d= 1.00 m

Distance between speakers and listener r= 4.00 m

Frequency = 300 Hz

Suppose we need to find the phase difference in radian between the waves from the speakers when they reach the observer

We need to calculate the r'

Using Pythagorean theorem

$r'=\sqrt{d^2+r^2}$

Where, d = distance between two identical loudspeakers

r = distance between speakers and listener

Put the value into the formula

$r'=\sqrt{(1.00)^2+(4.00)^2}$

$r'=\sqrt{1.00+16.00}$

$r'=4.12\ m$

We need to calculate the path difference

Using formula of path difference

$|r'-r|=4.12-4.00$

$|r'-r|=0.12\ m$

We need to calculate the wavelength

Using formula of wavelength

$\lambda=\dfrac{v}{f}$

Where, v = speed of sound

f = frequency

Put the value into the formula

$\lambda=\dfrac{343}{300}$

$\lambda=1.143\ m$

We need to calculate the phase difference

Using formula of phase difference

$\phi=\dfrac{2\pi\times|r'-r| }{\lambda}$

$\phi=\dfrac{2\pi\times0.12}{1.143}$

$\phi=0.659\ rad$

Hence, The phase difference is 0.659 rad.

7 0

3 years ago

Choose the sources of gamma rays. Check all that apply.

harina [27]

Answer:

a. Stars all warm objects

c. Some unstable atomic nuclei

Explanation:

Gamma rays are photons of very high energy (beyond 100keV) enough to remove an electron from its orbit.

They have a very short wavelength, less than 5 meters from the peak, and can be produced by nuclear decay, especially in the breasts of massive stars at the end of life.

They were discovered by the French chemist Paul Villard (1860 to 1934).

While X-rays are produced by electronic transitions in general caused by the collision of an electron with an atom at high speed, gamma rays are produced by nuclear transitions.

Gamma rays produce damage similar to those caused by X-rays or ultraviolet rays (burns, cancer and genetic mutations).

The sources of gamma rays that we observe in the universe come from <u>massive stars (hypernovas) or some warm objects on the space</u> that end their lives by a gravitational collapse that leads to the formation of a neutron star or a black hole, as well as <u>unstable radioactive nuclei </u>that emit radiation gamma to reach its steady state.

7 0

3 years ago

2. A wire 4.00 m long and 6.00 mm in diameter has a resistance of 15.0 mΩ. A potential difference of 23.0 V is applied between t

Vikentia [17]

Answer:

Explanation:

a )

current in the wire = potential diff / resistance

= 23 / (15 x 10⁻³ )

= 1.533 x 10³ A .

b )

For resistance of a wire , the formula is

R = ρ L / S where ρ is specific resistance , L is length and S is cross sectional area of wire

putting the given values

15 x 10⁻³ = 4ρ / π x .003²

ρ = 106 x 10⁻⁹ ohm. m

= 10.6 x 10⁻⁸ ohm m

The metal wire appears to be platinum .

4 0

3 years ago