Friction- the external force that acts on objects and causes them to slow down when no other external force acts upon them.
According to Newton (2nd law), Force = (mass) x (acceleration)
Substitute what we know : Force = (1,000 kg) x (3 m/s²)
Do the arithmetic: Force = 3,000 kg-m/s² = 3,000 newtons
Answer:
(
)=1913.31 N/m^2
Explanation:
given:
=0.85
=90 m/s
γ∞=1.23 kg/m^3
solution:
since outside pressure is atm pressure vaccum can be defined by ()
=√2()/γ∞[
-1]
()=1913.31 N/m^2
As this happens over twelve seconds, you would take the total difference in velocities and divide it by twelve to find the change per second
44.0 m/s - 2.0 m/s = 42.0 m/s
42.0 m/s / 12 s = 3.5 m/s2
the acceleration of the rock would be 3.5 m/s2
I'm not sure about the rest but for question 2:
A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.
