You are watching a magic show. For one trick the magician rolls a ball down a hill. Suddenly the ball stops moving down the hill
2 answers:
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Answer:
The balloon hit the ground with velocity -15.34 m/s
Explanation:
<em>Lets explain how to solve the problem</em>
You found that the best height to pitch a water balloon in order for it to
burst when it hits the ground is 12 meters.
We consider that the 12 meters is the maximum height, so the velocity
at this height is zero.
To find the velocity when the balloon hits the ground lets use the rule
<em>v² = u² + 2gh</em>, where v is the final velocity, u is the initial velocity, g is
the acceleration of gravity and h is the height.
u = 0 , h = 12 m , g = 9.8 m/s²
<em>Substitute these values in the equation above</em>
v² = 0 + 2(9.8)(12)
v² = 235.2
<em>Take square root for both sides</em>
v = ±
The velocity is downward, then it's a negative value
Then v = -15.34 m/s
<em>The balloon hit the ground with velocity -15.34 m/s</em>
Answer:
The number of atoms in the unit cell is 2, the crystal structure for the alloy is body centered cubic.
Explanation:
Given that,
Weight of metal A = 12.5%
Weight of metal B = 87.5%
Length of unit cell = 0.395 nm
Density of A = 4.27 g/cm³
Density of B= 6.35 g/cm³
Weight of A = 61.4 g/mol
Weight of B = 125.7 g/mol
We need to calculate the density of the alloy
Using formula of density
....(I)
Where, n = number of atoms per unit cells
m = Mass of the alloy
V=Volume of the unit cell
N = Avogadro number
We calculate the density of alloy
We calculate the mass of the alloy
Put the value into the equation (I)
Hence, The number of atoms in the unit cell is 2, the crystal structure for the alloy is body centered cubic.