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3 years ago

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The car traveled part of the route at an average speed of 60 km / h. then it traveled at 130 km / h, and the last section travel

ed at 80 km / h. What was the average speed if the entire 200 km route was completed in 2.5 hours? save calculations

1 answer:

frutty [35]3 years ago

7 0

Answer:

Explanation:

200/2.5

=80

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A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio

DanielleElmas [232]

Answer:

$\alpha =-2.2669642\times^{-10}rad/s^2$

Explanation:

Angular acceleration is defined by $\alpha =\frac{\Delta \omega}{\Delta t}=\frac{\omega_f-\omega_i}{\Delta t}$

Angular velocity is related to the period by $\omega=\frac{2\pi}{T}$

Putting all together:

$\alpha =\frac{\frac{2\pi}{T_f}-\frac{2\pi}{T_i}}{\Delta t}=\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})$

Taking our initial (i) point now and our final (f) point one year later, we would have:

$\Delta t=1\ year=(365)(24)(60)(60)s=31536000
s$

$T_i=0.0786s$

$T_f=0.0786s+7.03\times10^{-6}s$

So for our values we have:

$\alpha =\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})=\frac{2\pi}{31536000s}(\frac{1}{0.0786s+7.03\times10^{-6}s}-\frac{1}{0.0786s})=-2.2669642\times^{-10}rad/s^2$

Where the minus sign indicates it is decelerating.

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3 years ago

Prof. Kopp is working on an experiment located in an abandoned mine near Duluth, MN. The experiment is located approximately 713

MA_775_DIABLO [31]

Answer:

The average speed of the elevator going down in the abandoned mine is 17.722mph.

Explanation:

If the elevator takes 90 seconds to descend a height of 713m, the average speed of the elevator is:

$v_{av}=x_T/t_T=713m/90s=7.922m/s$

And if 1m/s is 2.23694mph, the average speed is:

$v_{av}=7.922m/s=17.722mph$ .

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3 years ago

geniusboy [140]

Answer:

a) b = -5

b) slope = 3/2

Explanation:

a) The equation of a line is given as y = mx + b, where m is the slope of the line and b is the intercept on the y axis.

Given that y = 3x + b and it passes through the point (2, 1). Hence when x = 2, y = 1. Therefore, substituting for x and y:

1 = 3(2) + b

1 = 6 + b

b = 1 - 6

b = -5

b) The equation of a line passing through two points ( $x_1,y_1$ ) and $x_2,y_2$ is given by:

$y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)$

The equation of the line passing through the two points (0,3) and (4,9) is:

$y-3=\frac{9-3}{4-0}(x-0)\\ \\y-3=\frac{3}{2}x\\ \\y = \frac{3}{2}x+3$

Comparing y = (3/2)x + 3 with y = mx + b, the slope (m) is 3/2

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3 years ago

A system dissipates 12 J of heat into the surroundings; meanwhile, 28 J of work is done on the system. What is the change of the

Stels [109]

Answer:

+16 J

Explanation:

We can solve the problem by using the 1st law of thermodynamics:

$\Delta U = Q-W$

where

$\Delta U$ is the change of the internal energy of the system

Q is the heat (positive if supplied to the system, negative if dissipated by the system)

W is the work done (positive if done by the system, negative if done by the surroundings on the system)

In this case we have:

Q = -12 J is the heat dissipated by the system

W = -28 J is the work done ON the system

Substituting into the equation, we find the change in internal energy of the system:

$\Delta U=-12 J-(-28 J)=+16 J$

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3 years ago

Which of the following statements is true about tides? (2 points)

andre [41]

1: <span>Tides are caused by the location of the Earth, sun, and moon.

2: </span><span>Tides occur about an hour later each day.
This is because of the earth's orbit and the moons position as they move.
</span><span>
3: </span>Half as much as the moon
The moon affects the tide much more than the sun, as the moon is drastically closer to the earth than the sun.

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3 years ago