-- The acceleration due to gravity is 32.2 ft/sec² . That means that the
speed of a falling object increases by an additional 32.2 ft/sec every second.
-- If dropped from "rest" (zero initial speed), then after falling for 4 seconds,
the object's speed is (4.0) x (32.2) = <em>128.8 ft/sec</em>.
-- 128.8 ft/sec = <em>87.8 miles per hour</em>
Now we can switch over to the metric system, where the acceleration
due to gravity is typically rounded to 9.8 meters/sec² .
-- Distance = (1/2) x (acceleration) x (time)²
D = (1/2) (9.8) x (4)² =<em> 78.4 meters</em>
-- At 32 floors per 100 meters, 78.4 meters = dropped from the <em>25th floor</em>.
The 5 points are certainly appreciated, but I do wish they were Celsius points.
Answer:
ΔE = 1.031 eV
Explanation:
For this exercise let's calculate the energy of the photons using Planck's equation
E = h f
wavelength and frequency are related
c = λ f
f = c /λ
let's substitute
E = h c /λ
let's calculate
E = 6.63 10⁻³⁴ 3 10⁸/1064 10⁻⁹
E = 1.869 10⁻¹⁹ J
let's reduce to eV
E = 1.869 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
E = 1.168 eV
therefore the electron affinity is
ΔE = E - 0.137
ΔE = 1.168 - 0.137
ΔE = 1.031 eV
dashed lines<span> represent bonds away from the viewer.</span>
The answer is A! Europe and South America
Answer:
a) the distances are zero, Both 1st & 2nd condition
c) the torques are equal but of the opposite sign, 2nd condition of equilibrium
Explanation:
The equilibrium conditions are
1 translational
∑ F = 0
2 rotational
∑ τ = Σ (F_i x r_i) = 0
They tell us that external torque is zero.
Therefore we have two various possibilities
a) the distances are zero, in this case we have a pure translation movement
for this situation the two equilibrium relations are fulfilled
b) the forces are zero, there is no movement
It does not make sense to use the equilibrium relations since there are no forces
c) the torques are equal but of the opposite sign, the forces are on the opposite side of the body.
In this case the 2 equilibrium relation is fulfilled, but not the first one that the force has the same direction
