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3 years ago

14

A car is traveling 20 meters per second and is brought to rest by applying brakes over a period of 4 seconds. What is the averag

e acceleration over this time interval

1 answer:

seraphim [82]3 years ago

8 0

It would be 0-20/4 so it’d be -5 meters per second

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Lightning produces a maximum air temperature on the order of 104K, whereas a nuclear explosion produces a temperature on the ord

gtnhenbr [62]

Answer:

tex]2.898\times 10^{-7}\ \text{m}[/tex] ultraviolet region

$2.898\times 10^{-10}\ \text{m}$ x-ray region

Explanation:

T = Temperature

b = Constant of proportionality = $2.898\times 10^{-3}\ \text{m K}$

$\lambda$ = Wavelength

$T=10^4\ \text{K}$

From Wein's law we have

$\lambda=\dfrac{b}{T}\\\Rightarrow \lambda=\dfrac{2.898\times 10^{-3}}{10^4}\\\Rightarrow \lambda=2.898\times 10^{-7}\ \text{m}$

The wavelength of the radiation will be $2.898\times 10^{-7}\ \text{m}$ and it is in the ultraviolet region.

$T=10^7\ \text{K}$

$\lambda=\dfrac{2.898\times 10^{-3}}{10^7}\\\Rightarrow \lambda=2.898\times 10^{-10}\ \text{m}$

The wavelength of the radiation will be $2.898\times 10^{-10}\ \text{m}$ and it is in the x-ray region.

5 0

2 years ago

A train car with mass m1 = 515 kg is moving to the right with a speed of v1 = 7.5 m/s and collides with a second train car. The

Anna [14]

Answer:

For the first situation, we first need to find the mass of the second train car.

In order to do that, we apply the conservation of the amount of movement:

$515*7.5+m2*0=(m1+m2)*4.8$

and we have as a result:

m2 = 289.6875

For the second situation, also we will apply the conservation of the amount of movement:

$515*7.5-289.6875*6 = (515+289.6875)*V$

and we have as a result:

V = 2.64 (it is moving to the right)

6 0

2 years ago

A(n) 1400-kg car going at 6.32 m/s in the positive x direction collides with a 2900-kg truck at rest. The collision is totally i

tresset_1 [31]

Answer:

a) Acceleration of the car is given as

$a_{car} = -21 m/s^2$

b) Acceleration of the truck is given as

$a_{truck} = 10.15 m/s^2$

Explanation:

As we know that there is no external force in the direction of motion of truck and car

So here we can say that the momentum of the system before and after collision must be conserved

So here we will have

$m_1v_1 + m_2v_2 = (m_1 + m_2)v$

now we have

$1400 (6.32) + 2900(0) = (1400 + 2900) v$

$v = 2.06 m/s$

a) For acceleration of car we know that it is rate of change in velocity of car

so we have

$a_{car} = \frac{v_f - v_i}{t}$

$a_{car} = \frac{2.06 - 6.32}{0.203}$

$a_{car} = -21 m/s^2$

b) For acceleration of truck we will find the rate of change in velocity of the truck

so we have

$a_{truck} = \frac{v_f - v_i}{t}$

$a_{truck} = \frac{2.06 - 0}{0.203}$

$a_{truck} = 10.15 m/s^2$

5 0

2 years ago

A light source emits light with dominant wavelengths in the range of 650 to 690 nm. what is the principle color of light emitted

dsp73

Answer:

Please see below as the answer is self-explanatory.

Explanation:

The visible range extends roughly from 400 nm (violet) to 700 nm (red).
Below the violet is the ultra-violet spectrum (with higher energy) and above red, we have the infra-red spectrum.
The wavelengths in the range of 650 to 690 nm have red as the dominant color.

6 0

2 years ago

Infer which group you would expect to contain element 117. Use the periodic table to help you answer this question.

Gre4nikov [31]

Answer:

halogen group

Explanation:

6 0

2 years ago