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
Answer:
Refraction
Explanation:
When light passes from a rarer medium into a denser medium, it bends in the medium away from the normal. This creates the phenomenon of "apparent depth" as given in the question.
When the object is moving in the elliptical orbit, it means that the direction of its acceleration should be towards the two foci (plural of focus) of the ellipse to keep the elliptical motion. As force according to the Newton's second law: F = ma, the net force must be in the direction of the acceleration. As far as the magnitude of net force is concerned, you can use Newton's gravitational law to find its magnitude.
To determine the diameter of the earth in metres first multiply the original value by 2.
6378 X 2 = 12 756 km.
Then convert km - m
1 km = 1000 m
12 756 km = ? m
12 756 • 1000 = 12 756 000 = 12 756 000 m or 1.2756 X 10 ^ 7 m
The final solution for the diameter is 1.2756 X 10 ^ 7 m.
Answer:
0.9 N
Explanation:
The force exerted on an object is related to its change in momentum by:

where
F is the force exerted
is the change in momentum
is the time interval
The change in momentum can be rewritten as

where
m is the mass
u is the initial velocity
v is the final velocity
So the formula can be rewritten as

In this problem we have:
is the mass rate
is the initial velocity
is the final velocity
Therefore, the force exerted by the hail on the roof is:
