Provides most of the energy used in the world today.

Two cars A and B, travel in a straight line. The distance of A from the starting point is given as a function of time by x????(?

Norma-Jean [14]

Answer:

a) They are in the same point

b) t = 0 s, t = 2.27 s, t = 5.73 s

c) t = 1 s, t = 4.33 s

d) t = 2.67 s

Explanation:

Given equations are:

$x_{a}(t) = at+bt^2$

$x_{b}(t) = ct^2-dt^3$

Constants are:

$a = 2.60 m/s, b = 1.20 m/s^2, c= 2.80 m/s^2, d = 0.20 m/s^3$

a) "Just after leaving the starting point" means that t = 0. So, if we look the equations, both $x_a(t)$ and $x_b(t)$ depend on t and don't have constant terms.

So both cars A and B are in the same point.

b) Firstly, they are in the same point in x = 0 at t = 0. But for generalized case, we must equalize equations and solve quadratic equation where roots will give us proper t value(s).

$at+bt^2 = ct^2-dt^3$

$2.6t + 1.2t^2 = 2.8t^2 - 0.2t^3\\0.2t^2 - 1.6t + 2.6 = 0\\t^2 - 8t + 13 = 0$

$t_1 = 4 - \sqrt{3} = 2.27$ s, $t_1 = 4 + \sqrt{3} = 5.73$ s

c) Since the distance isn't changing, the velocities are equal. To find velocities, we need to take the derivatives of both equations with respect to time and equalize them.

$v_a(t) = \frac{d}{d(t)}x_a(t) = a + 2bt \\v_b(t) = \frac{d}{d(t)}x_b(t) = 2ct - 3dt^2\\a+2bt = 2ct - 3dt^2\\3dt^2+2(b-c)t+a = 0\\0.6t^2-3.2t+2.6 = 0$

$t_1 = 1$ s, $t_2 = 4.33$ s

d) For same acceleration, we we need to take the derivatives of velocity equations with respect to time and equalize them.

$a_a(t) = \frac{d}{d(t)}v_a(t) = 2b \\a_b(t) = \frac{d}{d(t)}v_b(t) = 2c - 6dt\\2b = 2c - 6dt\\3dt = c - b\\t = (c - b)/3d = (2.8 - 1.2)/(3*0.2) = 2.67$ s

3 0

3 years ago

Read 2 more answers

Blood contains positive and negative ions and therefore is aconductor. A blood vessel, therefore, can be viewed as anelectrical

CaHeK987 [17]

Answer:

<h2>Magnetic field required for the given induced EMF is 1.41 T</h2>

Explanation:

Potential difference across the blood vessel is given as

$E = vBd$

here we know that the speed is given as

$v = 14.8 cm/s$

$d = 4.80 mm$

$E = 1 mV$

now we have

$1 \times 10^{-3} = (14.8 \times 10^{-2})B(4.80 \times 10^{-3})$

$B = 1.41 T$

Now volume flow rate of the blood is given as

$Q = Av$

$Q = \frac{\pi d^2v}{4}$

from above equation we have

$v = \frac{E}{Bd}$

Now we have

$Q = \frac{\pi d^2\frac{E}{Bd}}{4}$

$Q = \frac{\pi E d}{4B}$

5 0

3 years ago

True or False. Father of a multitude" obeyed God's command to kill His son because the Ten Commandments had not yet been given.

velikii [3]

Answer:

Explanation:

The father of the Multitude was Abraham. And he did precede the 10 commandments. But the story really has nothing to do with the 10 commandments.

He obeyed God's Command because it was God who issued it. Abraham had complete faith in God's ability to make things come out right. The sacrifice of Isaac was a test of faith.

I would advise you to answer true, but whoever wrote the question employed a twisted kind of logic. The sacrifice of Isaac had nothing to do with the 10 commandments. <u><em>Thou Shalt not murde</em></u>r is not really covered by this circumstance.

So true might not be the correct answer. The question is very complex and does not lend itself to a simple True/ False answer.

4 0

2 years ago

Describe 2 ways you could increase the efficiency of a household central heating system

chubhunter [2.5K]

Answer:

Arrange an annual service. Treat your boiler like your car. ...

Keep your boiler clean. ...

Bleed your radiators. ...

Top up the pressure. ...

Use a Powerflush. ...

Insulate your pipes. ...

Turn the heating on. ...

If all else fails…

Explanation:

6 0

3 years ago

How much 8 grams will weigh after a physical change

Ber [7]

I would look this one up on Google

5 0

3 years ago