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4 years ago

What is the average speed of a car that travels a distance of 10 km in 30 min?

Physics

1 answer:

Natali [406]4 years ago

4 0

Answer:

The average speed of a car is 20 km/h.

Explanation:

We have,

Distance covered by car is 10 km

Time taken by the car to cover that distance is 30 min. 30 min means 0.5 hours.

It is required to find the average speed of a car. It can be calculated using formula of average speed which is given by :

$v=\dfrac{d}{t}\\\\v=\dfrac{10\ km}{0.5\ h}\\\\v=20\ km/h$

So, the average speed of a car is 20 km/h.

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Douglas has a segment with endpoints I(5, 2) and J(9, 10) that is divided by a point K such that IK and KJ form a 2:3 ratio. He

Rufina [12.5K]

For the answer to the question above,
the distance from i to j is 5 parts
(2 parts from i to k and 3 parts from k to j)

The y distance from i to j is
10 - 2 = 8

Each part is 8/5 = 1.6
Therefore the distance between the 2 parts from i to k is 3.2

From the y coordinate of I which is 2 plus the 3.2 to point k
2 + 3.2 = 5.2

Answer y =5.2

Now just convert that to fraction and that will be the answer

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3 years ago

In a pilot study to help train a group of data collectors who will evaluate childrens pain using a FACES rating scale, the resea

muminat

Answer:

Option c. Inter-rater Reliability

Explanation:

Here, the rating is done by a group of data collectors under training for evaluation children's pain on Faces scale which is a scale ranging from 0 to 10 with different expressions or faces with a happy face at 0 to a crying face at 10.

Also in Inter-rater Reliability, the relative consistency of a study or test is assessed and the extent to which different group members rated the same behavior, the consistency of which is evaluated.

Thus it can also be helpful in interviews, etc.

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4 years ago

What happens if the breakdown voltage is exceeded.

s2008m [1.1K]

Answer:

this may help

Explanation:

maybe it will cause the eletric cause a fire that will mean it will spread till the fire men should come

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3 years ago

What will happen to force?

telo118 [61]

Answer:

it will double because im right

8 0

3 years ago

A photon of wavelength 2.78 pm scatters at an angle of 147° from an initially stationary, unbound electron. What is the de Brogl

Elena-2011 [213]

Answer:

2.07 pm

Explanation:

The problem given here is the very well known Compton effect which is expressed as

$\lambda^{'}-\lambda=\frac{h}{m_e c}(1-cos\theta)$

here, $\lambda$ is the initial photon wavelength, $\lambda^{'}$ is the scattered photon wavelength, h is he Planck's constant, $m_e$ is the free electron mass, c is the velocity of light, $\theta$ is the angle of scattering.

Given that, the scattering angle is, $\theta=147^{\circ}$

Putting the respective values, we get

$\lambda^{'}-\lambda=\frac{6.626\times 10^{-34} }{9.11\times 10^{-31}\times 3\times 10^{8} } (1-cos147^\circ ) m\\\lambda^{'}-\lambda=2.42\times 10^{-12} (1-cos147^\circ ) m.\\\lambda^{'}-\lambda=2.42(1-cos147^\circ ) p.m.\\\lambda^{'}-\lambda=4.45 p.m.$

Here, the photon's incident wavelength is $\lamda=2.78pm$

Therefore,

$\lambda^{'}=2.78+4.45=7.23 pm$

From the conservation of momentum,

$\vec{P_\lambda}=\vec{P_{\lambda^{'}}}+\vec{P_e}$

where, $\vec{P_\lambda}$ is the initial photon momentum, $\vec{P_{\lambda^{'}}}$ is the final photon momentum and $\vec{P_e}$ is the scattered electron momentum.

Expanding the vector sum, we get

$P^2_{e}=P^2_{\lambda}+P^2_{\lambda^{'}}-2P_\lambda P_{\lambda^{'}}cos\theta$

Now expressing the momentum in terms of De-Broglie wavelength

$P=h/\lambda,$

and putting it in the above equation we get,

$\lambda_{e}=\frac{\lambda \lambda^{'}}{\sqrt{\lambda^{2}+\lambda^{2}_{'}-2\lambda \lambda^{'} cos\theta}}$

Therefore,

$\lambda_{e}=\frac{2.78\times 7.23}{\sqrt{2.78^{2}+7.23^{2}-2\times 2.78\times 7.23\times cos147^\circ }} pm\\\lambda_{e}=\frac{20.0994}{9.68} = 2.07 pm$

This is the de Broglie wavelength of the electron after scattering.

6 0

4 years ago