All categories

3 years ago

Which of the materials would be able to scratch Quartz

1 answer:

7 0

<span>anything harder than mohs scale 7 so eg Topaz, Corundum and diamond representing mohs scale 8 9 and 10 respectively.</span>

You might be interested in

A student builds a rocket-propelled cart for a science project. Its acceleration is not quite high enough to win a prize, so he

irina [24]

Answer:

Explanation:

a = F / m

where a is acceleration , F is thrust and m is mass

taking log and differentiating

da / a = dF / F - dm / m

(da / a)x 100 = (dF / F)x100 - (dm / m) x100

percentage increase in a = percentage increase in F - percentage increase in m

= percentage increase in acceleration a = 39 - 13 = 26 %

required increase = 26 %.

5 0

3 years ago

The angular velocity of a 755-g wheel 15.0 cm in diameter is given by the equation ω(t) = (2.00 rad/s2)t + (1.00 rad/s4)t 3. (a)

Lunna [17]

Answer:

The number of radians turned by the wheel in 2s is $\theta= 8\ radians$

The angular acceleration is $\alpha =14 rad/s^2$

Explanation:

The angular velocity is given as

$w(t) = (2.00 \ rda/s^2)t + (1.00 rad /s^4)t^3$

Now generally the integral of angular velocity gives angular displacement

So integrating the equation of angular velocity through the limit 0 to 2 will gives us the angular displacement for 2 sec

This is mathematically evaluated as

$\theta(t ) = \int\limits^2_0 {2t + t^3} \, dt$

$= [\frac{2t^2}{2} + \frac{t^4}{4}] \left\{ 2} \atop {0}} \right.$

$= [\frac{2(2^2)}{2} + \frac{2^4}{4}] - 0$

$= 4 +4$

$\theta= 8\ radians$

Now generally the derivative of angular velocity gives angular acceleration

So the value of the derivative of angular velocity equation at t= 2 gives us the angular acceleration

This is mathematically evaluated as

$\frac{dw}{dt} = \alpha (t) = 2 + 3t^2$

so at t=2

$\alpha (2) = 2 +3(2)^2$

$\alpha =14 rad/s^2$

7 0

3 years ago

A student in gym class swings from a rope and they are moving 5 m/s at the bottom of their swing. What is the height they reach

vaieri [72.5K]

Answer:

Explanation:

4 0

3 years ago

What kind of change is it when a liquid turns into a gas by boiling????????????????????

elixir [45]

It is called vaporization. Vaporization is the phase transition from a liquid to a gas by means of evaporation or boiling. Evaporation occurs at temps below the boiling point and occurs on the liquids surface. Boiling is a rapid vaporization that occurs above the boiling temp and below or at the liquids surface.

5 0

4 years ago

Boats use echo sounders. Pulses of sound waves are reflected by the sea bed and

Sati [7]

Answer: depth = 3.75 m

Explanation:

Taken the speed of the sound in sea to be V = 1500 m/s

The time between an echo sounder sending and receiving a pulse is 0.005 s. That is,

Total time T = 0.005

Formula for echo is:

V = 2X/T

Where X = distance covered

Substitute V and T into the formula

1500 = 2X/0.005

Cross multiply

7.5 = 2X

Make X the subject of formula

X = 7.5/2

X = 3.75 m

Therefore, the depth of the sea is 3.75 m

4 0

3 years ago