As per Newton's II law we know that
rate of change in momentum is Net outside force on the object
now here we will have if net outside force will be zero
then we can say
so from above equation we can say
and hence we have
so the correct answer will be
<em>3.) in the absence of outside forces</em>
Not true. For all diseases caused by pathogens (even viruses), there is a minimum infectious dose needed to cause disease.
It does vary between different pathogens & between the condition of the host (immunocompromised vs. healthy), but if the minimum infectious dose is not met- then the body is typically able to snuff out the intruders before they can do any real damage.
Hope that helps!
Answer:
a) v = 75 ft / s
, b) v = 55 ft / s
, c) Δx = 1000 ft
Explanation:
We can solve this exercise with the expressions of kinematics
a) average speed is defined as the distance traveled in a given time interval
v = (x₂-x₁) / (t₂-t₁)
v = (550 - 400) / (10 -8)
v = 75 ft / s
b) we repeat the calculations for this interval
v = (550 - 0) / (10 -0)
v = 55 ft / s
c) we clear the distance from the average velocity equation
Δx = v (t₂ -t₁)
Δx = 100 (20-10)
Δx = 1000 ft