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4 years ago

Anyone know these questions?

Physics

1 answer:

salantis [7]4 years ago

7 0

400m in 32sec: (400/32)>12.5meters per second>
(12.5)(60)(60)(1/1000)=45km per hour
Constant speed would mean that the two forces are equivalent

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A sample of oxygen gas at 25.0Â°c has its pressure tripled while its volume is halved. What is the final temperature of the gas?

Marat540 [252]

Answer:

447 K

Explanation:

25 C = 25 + 273 = 298 K

Assuming ideal gas, we can apply the ideal gas law

$\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}$

$T_2 = T_1\frac{P_2}{P_1}\frac{V_2}{V_1}$

Since pressure is tripled, then $P_2 / P_1 = 3$ . Volume is halved, then $V_2 / V_1 = 0.5$

$T_2 = 298*3*0.5 = 447 K$

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3 years ago

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Dahasolnce [82]

This is Kinematics and the equations in your book.

A speed time graph would plot the speed of something against the teime it was at a speed.

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3 years ago

What is a statement that’s summarizes a pattern found in nature

sergey [27]

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3 years ago

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A 10 mH inductor is connected in series with a 10-ohm resistor, a switch and a 6-volt battery.(a) What is the time constant of t

maxonik [38]

Explanation:

It is given that,

Inductance of the inductor, $L=10\ mH=10\times 10^{-3}\ H=10^{-2}\ H$

Resistance of the resistor, R = 10 ohms

(a) Let $\tau$ is the time constant of the circuit. It is given by :

$\tau=\dfrac{L}{R}$

$\tau=\dfrac{10^{-2}}{10}$

$\tau=0.001\ s$

$\tau=1\ ms$

(b) The current equation in RL circuit is given by :

$I'=I(1-e^{\dfrac{-t}{\tau}})$

I' = 0.99 I

$0.99=1-e^{\dfrac{-t}{\tau}}$

$e^{\dfrac{-t}{\tau}}=0.01$

$e^{\dfrac{-t}{1\ ms}}=0.01$

t = 4.6 ms

Hence, this is the required solution.

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3 years ago

A rock is thrown off of a 100 foot cliff with an upward velocity of 45 m/s. As a result its height after t seconds is given by t

oee [108]

Q: A rock is thrown off of a 100 foot cliff with an upward velocity of 45 m/s. As a result its height after t seconds is given by the formula:

h(t)=100+45t−4.9t2

(a) What is its height after 3 seconds?

(b)What is its velocity after 3 seconds?

Answer:

(a) 190.9 m.

(b) 15.6 m/s upward

Explanation:

Given:

h(t) = 100 + 45t - 4.9t²

The height after 3 seconds,

t = 3 s

Substitute the value of t in to the equation above.

h(3) = 100+45(3)-4.9(3)²

h(3) = 100+135-44.1

h(3) = 190.9 m

Therefore the height after 3 seconds = 190.9 m.

(b) Velocity after 3 seconds

The velocity is obtained by differentiating h(t) with respect to time

v = dh(t)/dt

dh(t)/dt = 45-9.8t

v = 45 - 9.8t ......................................... Equation 1

t = 3 s.

Substitute the value of t into the equation above,

v = 45 - 9.8(3)

v = 45- 29.4

v = 15.6 m/s

Thus the velocity after 3 seconds = 15.6 m/s upward

3 0

4 years ago