The mineral with Mohs hardness would be scratched because the mineral with Mohs 7 hardness is stronger than the Mohs 5 mineral. Eventually, that mineral would turn into dust if you kept rubbing it.
Answer:
1) D
2) A
Explanation:
1) Each group has the same number of valence electrons, which are the outer electrons.
2) Ionic bonds are between a metal and non - metal, the metal being sodium and the non - metal being chlorine.
Really, Gundy ? ! ?
The formula for the car's speed is given and discussed in the box. The formula is
v = √(2·g·μ·d)
Then they <em>tell</em> you that μ is 0.750 , and then they <em>tell</em> you that d = 52.9 m . Also, everybody knows that 'g' is gravity = 9.8 m/s² .
They also tell us that the mass of the car is 1,000 kg, and they tell us that it took 3.8 seconds to skid to a stop. But we already <em>have</em> all the numbers in the formula <em>without</em> knowing the car's mass or how long it took to stop. The police don't need to weigh the car, and nobody was there to measure how long the car took to stop. All they need is the length of the skid mark, which they can measure, and they'll know how fast the guy was going when he hit the brakes !
Now, can you take the numbers and plug them into the formula ? ! ?
v = √(2·g·μ·d)
v = √( 2 · 9.8 m/s² · 0.75 · 52.9 m)
v = √( 777.63 m²/s²)
v = 27.886 m/s
Rounded to 3 digits, that's <em>27.9 m/s </em>.
That's about 62.4 mile/hour .
Answer:
Revolutions made before attaining angular velocity of 30 rad/s:
θ = 3.92 revolutions
Explanation:
Given that:
L(final) = 10.7 kgm²/s
L(initial) = 0
time = 8s
<h3>
Find Torque:</h3>
Torque is the rate of change of angular momentum:
<h3>Find Angular Acceleration:</h3>
We know that
T = Iα
α = T/I
where I = moment of inertia = 2.2kgm²
α = 1.34/2.2
α = 0.61 rad/s²
<h3>
Find Time 't'</h3>
We know that angular equation of motion is:
ω²(final) = ω²(initial) +2αθ
(30 rad/s)² = 0 + 2(0.61 rad/s²)θ
θ = (30 rad/s)²/ 2(0.61 rad/s²)
θ = 24.6 radians
Convert it into revolutions:
θ = 24.6/ 2π
θ = 3.92 revolutions
