Answer:
ok............I'll try ............
The density of the metal can be determined through the formula [n*MW]/ Na*[a^3] . substituting, we get,
<span>d = [n*MW]/ Na*[a^3]
</span><span>d = [4 atoms*42.3 g/mol]/ [6.022 x 1023atoms/mol* (sqrt 8 *1.20x10-10)^3]
</span>d = 0.719 g/cm3
Answer:
45.6m
Explanation:
The equation for the position y of an object in free fall is:
With the given values in the question the equation has one unknown v₀:
Solving for t=1:
1) 
To find the hight of the tower you can use the concept of energy conservation:
The energy of the body 1 sec before it hits the ground:
2) 
If h is the height of the tower, the energy on top of the tower:
3) 
Combining equation 2 and 3 and solving for h:
4) 
Combining equation 1 and 4:
Answer:
See explanation
Explanation:
In this exercise, we need to use the law of conservation of angular momentum which is:
I1*W1 + I2*W2 = (I1 + I2)*W2'
Where:
I: moment of innertia.
W: angular velocity
Now let's call 1 the runner and 2, the turntable. the system would be W2'.
The angular speed of the runner, we can calculate that with the following expression:
W = V/r
so:
W1 = 2.5 / 3.6 = 0.694 rad/s
The innertia is calculated with the expression:
I = m*r²
I = 60 * 3.6 = 216 kg.m²
I2 and W2 are provided in the exercise, so, replacing all the data in the conservation of angular momentum, let's solve for W2'
(216*0.694) + (-0.190*81) = (81 + 216)W2'
134.514 = 297W2'
W2' = 134.514 / 297
W2' = 0.453 rad/s
