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
Speed is scalar, meaning it's only going to be like 74 mph, doesn't matter which direction. Velocity is a vector, meaning it has direction. You can go -74mph when talking about velocity, not speed.
Answer:
wavelength 
= 437.27 nm
Explanation:
given data
first bright fringe = 2.96 mm
slit separation = 0.325 mm
distance D = 2.20 m
solution
we know that this is double slit experiment
so we apply here Fringe width formula that is
β = 
....................1
is Wavelength of light and D is Distance between screen and slit and d is slit width
so put here value and we get
= 
= 437.27 × 
m
wavelength = 437.27 nm
In physics, power is defined as energy per unit time. You will also hear it described as work per unit time. The standard unit of measure for power is the watt, where a watt is defined as joules (energy) per second (time). This is expressed as a fraction as J/s. If you wanted to increase the power in any operation, you can either increase the energy (more joules) or reduce the time (fewer seconds).
