How are kyanite crystals formed

[Please help fast! Offering 100 points if it works!}

solmaris [256]

Answer:

d=1.49×1011m

Explanation:

Velocity is defined as the rate of travel, and can be found using the distance formula.

velocity=distancetime

Rearranging this formula we can solve for distance given velocity and time of travel.

d=vt

We are given velocity and time, and so can solve for distance, but if we plug in the values given;

d=(3.00×108m/s)(8.3minutes)

We can see that the units do not match up. Since seconds are the SI unit for time, we will need to convert 8.3 minutes to seconds.

t=(8.3minutes)(60seconds/minute)=(498s)

Now our units work out and we can solve for distance.

= 15.85

3 0

3 years ago

Read 2 more answers

To determine the trajectory of the movement of a material point in the xOz plane that is subjected simultaneously to oscillation

nasty-shy [4]

We are to show that the given parametric curve is a circle.

The trajectory of a circle with a radius r will satisfy the following relationship:

$(x-x_c)^2 + (y-y_c)^2 = r^2$

(with (x_c,y_c) being the center point)

We are given the x and y in a parametric form which can be further rewritten (using properties of sin/cos):

$x(t) = A\sin \pi(t+1) = A\sin (\pi t + \pi) = -A\sin \pi t\\y(t) = A\sin (\pi t + \frac{\pi}{2}) = A\cos \pi t$

Squaring and adding both gives:

$x^2(t) + y^2(t) = A^2(-1)^2\sin^2 \pi t + A^2 \cos^2 \pi t = A^2\\\implies x^2 + y^2 = A^2$

The last expression shows that the given parametric curve is a circle with the center (0,0) and radius A.

4 0

3 years ago

A tradesman sharpens a knife by pushing it with a constant force against the rim of a grindstone. The 30-cm-diameter stone is sp

Lorico [155]

Answer:

a. 0.21 rad/s2

b. 2.205 N

Explanation:

We convert from rpm to rad/s knowing that each revolution has 2π radians and each minute is 60 seconds

200 rpm = 200 * 2π / 60 = 21 rad/s

180 rpm = 180 * 2π / 60 = 18.85 rad/s

r = d/2 = 30cm / 2 = 15 cm = 0.15 m

a)So if the angular speed decreases steadily (at a constant rate) from 21 rad/s to 18.85 rad/s within 10s then the angular acceleration is

$\alpha = \frac{\Delta \omega}{\Delta t} = \frac{21 - 18.85}{10} = 0.21 rad/s^2$

b) Assume the grind stone is a solid disk, its moment of inertia is

$I = mR^2/2$

Where m = 28 kg is the disk mass and R = 0.15 m is the radius of the disk.

$I = 28*0.15^2/2 = 0.315 kgm^2$

So the friction torque is

$T_f = I\alpha = 0.315*0.21 = 0.06615 Nm$

The friction force is

$F_f = T_f/R = 0.06615 / 0.15 = 0.441 N$

Since the friction coefficient is 0.2, we can calculate the normal force that is used to press the knife against the stone

$N = F_f/\mu = 0.441/0.2 = 2.205 N$

7 0

3 years ago

It takes a bus driver 30 minutes to pick up students from four stops. The last stop is at the corner of Green Street and Route 7

deff fn [24]

Answer:

No, the distance from the last stop to the school and the time it takes to travel that distance are required.

7 0

3 years ago

If six moles of hydrogen chloride (HCl) react with plenty of aluminum, how many moles of aluminum chloride (AlCl3) will the reac

AlexFokin [52]

Answer:

Two moles of aluminum chloride $(AlCl_3)$ are produced when six miles of hydrogen Chloride $(HCl)$ react with plenty of aluminum

Explanation:

6 Moles of $HCl$ will only react with 2 moles of $Al$ irrespective of the number of moles of each compound present. The reaction wiil take place in this ratio only. The products produced will be 2 moles of $AlCl_3$ and 3 moles of $H_2$ this ratio will also be constant.

So, six moles of hydrogen chloride $(HCl)$ will react with plenty of aluminum to produce many 2 moles of aluminum chloride $(AlCl_3)$ .

5 0

3 years ago