They discovered a vaccine to reduce illnesses, specifically Polio and Influenza. The work of Salk and Sabin has almost eradicated what was once a deadly disesase ( polio) . For example, there were 350,000 deaths related to poliovirus across the world in 1988 and they reduced to 22 in 2017. Also, their work has saved millions of lives from polio induced paralysis
interesting question.
how much fuel to hover over one place ?
The Foucault pendulum is a v v v long pendulum which can show the eart's rotation over time if the pend bob motion is tracked and recorded
Answer:
λ = 2.7608 x 10⁻⁷ m = 276.08 nm
Explanation:
The work function of a metallic surface is the minimum amount of photon energy required to release the photo-electrons from the surface of metal. The work function is given by the following formula:
Work Function = hc/λ
where,
Work Function = (4.5 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 7.2 x 10⁻¹⁹ J
h = Plank's Constant = 6.626 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = longest wavelength capable of releasing electron.
Therefore,
7.2 x 10⁻¹⁹ J = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/λ
λ = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(7.2 x 10⁻¹⁹ J)
<u>λ = 2.7608 x 10⁻⁷ m = 276.08 nm</u>
Answer:
A.) V = 14 m/s
B.) h = 36.6 m
Explanation:
Given the formula v = √2gh
where g = 9.8m/sec^2 is the acceleration due to gravity.
A.) Determine the impact velocity for an object dropped from a height of 10 m.
Substitute height h in the given formula
V = √2gh
V = √2 × 9.8 × 10
V = √196
V = 14 m/s
b. Determine the height required for an object to have an impact velocity of 26.8 m/sec (~ 60 mph). Round to the nearest tenth of a meter.
Substitute the velocity in the given formula and make height h the subject of formula.
26.8 = √2 × 9.8 × h
Square both sides
718.24 = 19.6h
h = 718.24 / 19.6
h = 36.64 m
h = 36.6 m
They represent the most simplified form of the compounds' formula.
